Document:

Exhibit 10.3

 

COMPANY STOCKHOLDER SUPPORT AGREEMENT

 

This Support Agreement (this
 “Agreement”), dated as of March 8, 2022, is entered into by and among AMCI Acquisition Corp. II, a Delaware
corporation (“Acquiror”) and certain of the stockholders (such stockholders, each, a “Stockholder”
and together, the “Stockholders”) of LanzaTech NZ, Inc., a Delaware corporation (the “Company”),
whose names appear on the signature pages of this Agreement.

 

RECITALS

 

WHEREAS, Acquiror, AMCI Merger
Sub, Inc., a Delaware corporation and a wholly owned subsidiary of Acquiror (“Merger Sub”) and the Company
have entered into an Agreement and Plan of Merger, dated as of the date hereof (as amended, supplemented, restated or otherwise modified
from time to time, the “Merger Agreement”; capitalized terms used but not otherwise defined in this Agreement
shall have the meanings ascribed to them in the Merger Agreement), pursuant to which (and subject to the terms and conditions set forth
therein) Merger Sub will merge with and into the Company, with the Company surviving the merger (the “Merger”);

 

WHEREAS, as of the date hereof,
each Stockholder is the record and “beneficial owner” (as such term is used herein, within the meaning of Rule 13d-3
under the Exchange Act) of, and is entitled to dispose of and vote, the number of Company Common Shares and Company Preferred Shares set
forth opposite such Stockholder’s name on Exhibit A hereto (collectively, with respect to each Stockholder, such Stockholder’s
 “Owned Shares”; and such Owned Shares, together with any additional Company Shares (or any securities convertible into
or exercisable or exchangeable for Company Shares) in which such Stockholder acquires record or beneficial ownership after the date hereof,
including by purchase, as a result of a stock dividend, stock split, recapitalization, combination, reclassification, exchange or change
of such shares, or upon exercise or conversion of any securities, the “Covered Shares”); and

 

WHEREAS, the Stockholders
are entering into this Agreement as a condition and inducement to the willingness of Acquiror and Merger Sub to enter into the Merger
Agreement.

 

AGREEMENT

 

NOW, THEREFORE, in consideration
of the foregoing and the mutual covenants and agreements herein contained, and intending to be legally bound hereby, Acquiror, Merger
Sub and each Stockholder hereby agree as follows:

 

1.             Agreement
to Vote. Subject to the earlier termination of this Agreement in accordance with Section 4, each Stockholder, solely in
such Person’s capacity as a stockholder of the Company, irrevocably and unconditionally agrees to validly execute and deliver to
the Company in respect of all of the Stockholder’s Covered Shares, as promptly as practicable after the Registration Statement becomes
effective (and in any event within ten (10) Business Days after receiving notice from Acquiror or the Company of such fact), the
written consent that will be solicited by the Company from the Stockholder pursuant to the Merger Agreement to obtain the Company Stockholder
Approval. In addition, prior to the Termination Date (as defined below), each Stockholder, in his, her or its capacity as a stockholder
of the Company, irrevocably and unconditionally agrees that, at any meeting of the stockholders of the Company (whether annual or special
and whether or not an adjourned or postponed meeting, however called and including any adjournment or postponement thereof) and in connection
with any written consent of stockholders of the Company, such Stockholder shall:

 

(a)             when
such meeting is held, appear at such meeting or otherwise cause such Stockholder’s Covered Shares to be counted as present thereat
for the purpose of establishing a quorum;

 

     

     

    

 

(b)             vote
(or execute and return an action by written consent), or cause to be voted at such meeting (or validly execute and return and cause such
consent to be granted with respect to), all of such Stockholder’s Covered Shares owned as of the record date for such meeting (or
the date that any written consent is executed by such Stockholder) in favor of (i) the adoption of the Merger Agreement and, as applicable,
the approval of each applicable Ancillary Agreement, and the transactions contemplated thereby (including the Company Share Conversion
and the Merger), and each other matter required (or reasonably requested by the Company or the Acquiror) to be approved or adopted by
the stockholders of the Company in order to effect the Merger and the other transactions contemplated by the Merger Agreement and the
Ancillary Agreements, and (ii) any proposal to adjourn such meeting at which there is a proposal for stockholders of the Company
to adopt the Merger Agreement to a later date if there are not sufficient votes to adopt the Merger Agreement or if there are not sufficient
Company Shares present in person or represented by proxy at such meeting to constitute a quorum; and

 

(c)             vote
(or execute and return an action by written consent), or cause to be voted at such meeting (or validly execute and return and cause such
consent to be granted with respect to), all of such Stockholder’s Covered Shares against (i) any Acquisition Proposal and (ii) any
other action that would reasonably be expected to (A) materially impede, interfere with, delay, postpone or adversely affect the
Merger or any of the other transactions contemplated by the Merger Agreement, (B) to the knowledge of such Stockholder, result in
a material breach of any covenant, representation or warranty or other obligation or agreement of the Company under the Merger Agreement
or (C) result in a material breach of any covenant, representation or warranty or other obligation or agreement of such Stockholder
contained in this Agreement.

 

The obligations of each Stockholder specified
in this Section 1 shall apply whether or not the Merger or any action described above is recommended by the Company Board
or the Company Board has previously recommended the Merger but changed such recommendation.

 

2.             No
Inconsistent Agreements. Each Stockholder hereby covenants and agrees that such Stockholder shall not, at any time prior to
the Termination Date, (a) enter into any voting agreement or voting trust with respect to any of such Stockholder’s Covered
Shares that is inconsistent with such Stockholder’s obligations pursuant to this Agreement, (b) grant a proxy or power of attorney
with respect to any of such Stockholder’s Covered Shares that is inconsistent with such Stockholder’s obligations pursuant
to this Agreement or (c) enter into any Contract or undertaking that is otherwise inconsistent with, or would interfere with, or
prohibit or prevent him, her or it from satisfying, his, her or its obligations pursuant to this Agreement.

 

3.             Termination
of Company Stockholder Agreements. Each Stockholder agrees to execute and deliver such agreement or instrument as may be necessary
to cause to be terminated, as at the Effective Time, each of the Company Voting Agreement, the Company ROFR and Co-Sale Agreement and
the Company Investors’ Rights Agreement, in each case subject to the survival of those provisions contained in each such Company
Stockholder Agreement that survive such termination in accordance with the express terms of such Company Stockholder Agreement.

 

4.             Termination.
This Agreement shall terminate upon the earliest of (a) the Effective Time, (b) the valid termination of the Merger Agreement
in accordance with its terms and, (c) with respect to each Stockholder, the mutual written agreement of Acquiror and such Stockholder
and (d) with respect to each Stockholder, the election by such Stockholder in his, her or its sole discretion to terminate this Agreement
following any amendment to, or waiver by the Company of Acquiror’s obligations under, the Merger Agreement without the prior written
consent of such Stockholder (which consent shall not be unreasonably withheld, conditioned or delayed) that materially decreases or changes
the form of the Merger Consideration; provided that reductions in the trading price of Acquiror Common Shares shall not constitute
a decrease in the Merger Consideration payable to such Stockholder for purposes of this Section 4 (the earliest of such date
under clause (a), (b), (c) and (d) being referred to herein as the “Termination Date”). In the event of the
termination of this Agreement pursuant to this Section 4, this Agreement shall forthwith become void and have no further force
or effect, without any Liability on the part of any party, other than for any Willful Breach of this Agreement occurring prior to such
termination, except that the provisions of this Section 4, and Sections 11, 12, 13, 14, 15,
16, 18, 20 and 21 shall survive any termination of this Agreement and shall remain legal, valid, binding and
enforceable obligations of the parties in accordance with their respective terms.

 

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5.             Representations
and Warranties of the Stockholders. Each Stockholder hereby represents and warrants (severally and not jointly as to himself, herself
or itself only) to Acquiror as follows:

 

(a)             As
of the date hereof, such Stockholder owns exclusively of record (and is the sole beneficial owner of), and has good, valid and marketable
title to, such Stockholder’s Owned Shares, free and clear of any Liens (other than as created by this Agreement, the Governing Documents
of the Company, any Company Stockholder Agreement or any applicable Laws). As of the date hereof, other than the Owned Shares set forth
opposite such Stockholder’s name on Exhibit A, such Stockholder does not own (of record or beneficially) any Company
Shares (or any securities convertible into shares of capital stock or other voting securities of the Company) or any interest therein.

 

(b)             As
of the date hereof, and except as provided in this Agreement or any Company Stockholder Agreement, such Stockholder (i) has full
voting power, full power of disposition and full power to issue instructions with respect to the matters set forth herein with respect
to such Stockholder’s Owned Shares, (ii) has not entered into any voting agreement or voting trust, and has no knowledge and
is not aware of any such voting agreement or voting trust in effect, with respect to any of such Stockholder’s Owned Shares that
is inconsistent with such Stockholder’s obligations pursuant to this Agreement, (iii) has not granted a proxy or power of attorney
with respect to any of such Stockholder’s Owned Shares that is inconsistent with such Stockholder’s obligations pursuant to
this Agreement, and has no knowledge and is not aware of any such proxy or power of attorney in effect, and (iv) has not entered
into any Contract or undertaking that is otherwise inconsistent with, or would interfere with, or prohibit or prevent him, her or it from
satisfying, his, her or its obligations pursuant to this Agreement and has no knowledge and is not aware of any such Contract or undertaking.

 

(c)             If
such Stockholder is not an individual, such Stockholder (i) is a legal entity duly organized, validly existing and, to the extent
such concept is applicable, in good standing under the Laws of the jurisdiction of its organization, and (ii) has all requisite corporate
or other power and authority and has taken all corporate or other action necessary in order to, execute, deliver, and perform its obligations
under, this Agreement, and to consummate the transactions contemplated hereby. If the Stockholder is an individual, he or she has all
the requisite capacity to execute and deliver this Agreement, to perform his or her obligations hereunder and to consummate the transactions
contemplated hereby. This Agreement has been duly executed and delivered by such Stockholder and constitutes a legally valid and binding
agreement of such Stockholder, enforceable against such Stockholder in accordance with the terms hereof (except as enforceability may
be limited by any Enforceability Exceptions).

 

(d)             Other
than the filings, notices and reports pursuant to, in compliance with or required to be made under the Exchange Act, no filings, notices,
reports, consents, registrations, approvals, permits, waivers, expirations of waiting periods or authorizations are required to be obtained
by such Stockholder from, or to be given by such Stockholder to, or be made by such Stockholder with, any Governmental Authority in connection
with the execution, delivery and performance by such Stockholder of this Agreement, the consummation of the transactions contemplated
hereby or the Merger or the other transactions contemplated by the Merger Agreement.

 

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(e)             The
execution, delivery and performance of this Agreement by such Stockholder does not, and the consummation of the transactions contemplated
hereby and the Merger and the other transactions contemplated by the Merger Agreement, will not (i) if such Stockholder is not an
individual, constitute or result in a breach or violation of, or a default under, the Governing Documents of such Stockholder, (ii) with
or without notice, lapse of time or both, constitute or result in a breach or violation of, a termination (or right of termination) of
or a default under, the loss of any benefit under, or the creation, modification or acceleration of any obligations under, any Contract
binding upon such Stockholder, in each case in a manner that would reasonably be expected to prevent or materially delay or materially
impair such Stockholder’s ability to perform his, her or its obligations hereunder or to consummate the transactions contemplated
by this Agreement, the consummation of the Merger or any other transaction contemplated by the Merger Agreement, or (iii) conflict
with or violate any Law to which such Stockholder is subject, (iv) require any consent, approval or authorization of, declaration,
filing or registration with, or notice to, any Person, in each case the absence of which would reasonably be expected to prevent or materially
delay or materially impair such Stockholder’s ability to perform his, her or its obligations hereunder or to consummate the transactions
contemplated by this Agreement, the consummation of the Merger or any other transaction contemplated by the Merger Agreement, or (v) constitute
or result in the creation of any Lien on such Stockholder’s Covered Shares, except for any Lien under applicable securities Laws
or any Lien created by Acquiror or its Affiliates.

 

(f)             As
of the date hereof, (i) there are no Actions pending against such Stockholder or, to the knowledge of such Stockholder, threatened
against such Stockholder and (ii) such Stockholder is not a party to or subject to the provisions of any Governmental Order, in each
case in clauses (i) or (ii), that, in any manner, questions the beneficial or record ownership of such Stockholder’s Covered
Shares or challenges or seeks to prevent, enjoin, impair, adversely affect or materially delay the performance by such Stockholder of
his, her or its obligations under this Agreement.

 

(g)             Such
Stockholder is a sophisticated stockholder and has adequate information concerning the business and financial condition of Acquiror and
the Company to make an informed decision regarding this Agreement and the other transactions contemplated by the Merger Agreement and
has independently, based on such information as the Stockholder has deemed appropriate and without reliance upon Acquiror, the Company
or any Affiliate of Acquiror or the Company, made his, her or its own analysis and decision to enter into this Agreement. Such Stockholder
acknowledges that that he, she or it has had the opportunity to seek independent legal advice prior to executing this Agreement. Acquiror
and the Company have not made and do not make any representation or warranty, whether express or implied, of any kind or character to
such Stockholder regarding the subject matter of this Agreement except as expressly set forth in this Agreement. Such Stockholder acknowledges
receipt and review of a copy of the Merger Agreement and that the agreements contained herein with respect to the Covered Shares held
by the Stockholder are irrevocable.

 

(h)             Such
Stockholder understands and acknowledges that Acquiror is entering into the Merger Agreement in reliance upon such Stockholder’s
execution and delivery of this Agreement and the representations, warranties, covenants and other agreements of such Stockholder contained
herein.

 

(i)             Except
as set forth in Section 5.17 of the Company Disclosure Letter, no investment banker, broker, finder or other intermediary is entitled
to any broker’s, finder’s, financial advisor’s or other similar fee or commission for which Acquiror or the Company
is or could be liable in connection with this Agreement or the Merger Agreement or any of the respective transactions contemplated hereby
or thereby, in each case based upon arrangements made by or on behalf of such Stockholder.

 

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6.             Certain
Covenants of the Stockholders. Except in accordance with the terms of this Agreement, each Stockholder hereby covenants and agrees
as follows:

 

(a)             No
Solicitation. Prior to the termination of this Agreement, such Stockholder shall not, and shall cause his, her or its controlled Affiliates
not to, and shall use reasonable best efforts to cause his, her or its and their respective Representatives not to, (i) initiate,
solicit, enter into or continue discussions, negotiations or transactions with, or respond to any inquiries or proposals by, any Person
with respect to, or provide any non-public information or data concerning the Company or any of the Company’s Subsidiaries to any
Person relating to, an Acquisition Proposal (other than to inform such Person of such Stockholder’s obligations pursuant to this
Section 6(a)), (ii) enter into any acquisition agreement, business combination agreement, merger agreement or similar
definitive agreement, or any letter of intent, memorandum of understanding or agreement in principle, or any other agreement relating
to an Acquisition Proposal, (iii) approve, endorse or recommend, or propose publicly to approve, endorse or recommend, any Acquisition
Proposal, (iv) grant any waiver, amendment or release under any confidentiality agreement or the anti-takeover laws of any state
for purposes of facilitating an Acquisition Proposal, (v) otherwise knowingly encourage or facilitate any such inquiries, proposals,
discussions, or negotiations or any effort or attempt by any Person to make an Acquisition Proposal or (vi) resolve or agree to do
any of the foregoing. Such Stockholder also agrees that immediately following the execution of this Agreement he, she or it shall, and
shall cause each of his, her or its controlled Affiliates to, and shall instruct his, her or its and their Representatives to, cease any
solicitations, discussions or negotiations with any Person (other than the parties hereto and their respective Representatives) conducted
heretofore in connection with an Acquisition Proposal or any inquiry or request for information that would reasonably be expected to lead
to, or result in, an Acquisition Proposal.

 

Notwithstanding anything in
this Agreement to the contrary, (x) such Stockholder shall not be responsible for the actions of the Company or the Company Board
(or any committee thereof), any Subsidiary of the Company, or any officers, directors (in their capacity as such), employees and professional
advisors of any of the foregoing (collectively, the “Company Related Parties”), (y) such Stockholder makes no
representations or warranties with respect to the actions of any of the Company Related Parties and (z) any breach by the Company
of its obligations under Section 7.5 of the Merger Agreement shall not in itself be considered a breach of this Section 6(a) (it
being understood that, for the avoidance of doubt, such Stockholder shall remain responsible for his, her or its breach of this Section 6(a) or
any breach of this Section 6(a) by his, her or its Representatives (other than any such Representative that is acting
in its capacity as a Company Related Party).

 

(b)             Restrictions
on Transfers. Prior to the termination of this Agreement, such Stockholder shall not, directly or indirectly, Transfer (as such term
is defined below) any of his, her or its Covered Shares, except (i) to an Affiliate of such Stockholder, (ii) by virtue of applicable
law or such Stockholder’s organizational documents upon liquidation or dissolution of such Stockholder or (iii) in case such
Stockholder is an individual, (A) to any member of such Stockholder’s immediate family (i.e., spouse, lineal descendant or
antecedent, brother or sister, adopted child or grandchild or the spouse of any child, adopted child, grandchild or adopted grandchild),
(B) to a trust for the sole benefit of such Stockholder or any member of such Stockholder’s immediate family, (C) to a
charity, charitable trust, or other charitable organization under Section 501(c)(3) of the Code, (D) upon the death of
such Stockholder or (E) for bona fide estate planning purposes; provided in each case in clauses (i) through (iii) that
such transferee signs a counterpart to this Agreement. As used herein, “Transfer” means (A) any sale, assignment,
exchange, conveyance, pledge, hypothecation or other transfer or disposition, whether direct or indirect, whether or not for value, and
whether or not by operation of law (including by merger, consolidation or otherwise), including any transfer of a Covered Share to a broker
or other nominee (with or without a corresponding change in beneficial ownership) and any transfer of voting control of such Covered Share,
or (B) entering into any Contract providing for any transaction contemplated by the preceding clause (A).

 

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7.            Appraisal
Rights; Other Actions. Each Stockholder (a) waives, and agrees not to assert or perfect, any rights of appraisal or rights to
dissent from the Merger or any other transaction contemplated by the Merger Agreement that such Stockholder may have by virtue of ownership
of the Covered Shares; and (b) except with respect to the enforcement of rights or remedies under the Merger Agreement or any Ancillary
Agreement (including in connection with a breach of any provision thereof or the termination thereof) agrees not to commence, join in,
facilitate, assist, encourage or participate in, and to take all actions necessary to opt out of any class in any class action with respect
to, any action or claim, derivative or otherwise, against Acquiror, Acquiror’s Affiliates, the Acquiror’s directors or officers,
the Sponsor, the Company or any of their respective successors and assigns relating to the evaluation, negotiation, execution or delivery
of this Agreement, the Merger Agreement (including the Merger Consideration) or the consummation of the transactions contemplated hereby
and thereby.

 

8.             Disclosure,
Public Announcements. Each Stockholder hereby authorizes the Company and Acquiror to publish and disclose in any announcement, filing
or disclosure required to be made by any Governmental Order or other applicable Law or the rules of any national securities exchange
or as requested by the SEC such Stockholder’s identity and ownership of the Covered Shares and the nature of such Stockholder’s
obligations under this Agreement; provided that, for the avoidance of doubt, such Stockholder’s identity shall not be included
in a press release or other public disclosure (other than a filing with the SEC) without such Stockholder’s prior written consent.
Neither the Stockholder nor any of his, her or its Affiliates shall issue any press release or make any other public announcement or public
statement with respect to this Agreement, the Merger Agreement or any of the transactions contemplated hereby or thereby (each, a “Public
Communication”), without the prior written consent of Acquiror and the Company (which consent may be withheld in Acquiror’s
or the Company’s sole discretion), except (a) as required by applicable Law or any Governmental Authority of competent jurisdiction
(including pursuant to any court process), in which case the Stockholder shall provide each of Acquiror and the Company and their respective
legal counsel with a reasonable opportunity to review and comment on such Public Communication (solely with respect to such portions that
relate to this Agreement, the Merger Agreement or the transactions contemplated hereby or thereby) in advance of its issuance and shall
give reasonable and good faith consideration to any such comments or (b) with respect to a Public Communication that is consistent
with prior disclosures by Acquiror and the Company; provided that the foregoing shall not apply to any disclosure required to be
made by such Stockholder to a Governmental Authority so long as such disclosure is consistent with the terms of this Agreement and the
Merger Agreement and the disclosures made by the Company and Acquiror pursuant to the terms of the Merger Agreement.

 

9.            Changes
in Capital Stock. In the event (a) of any change in the Company’s capital stock by reason of any split-up, reverse stock
split, recapitalization, combination, reclassification, exchange of shares or the like that results in a change in the number of Company
Shares held by each Stockholder, (b) any Stockholder purchases or otherwise acquires beneficial ownership of any Company Shares or
(c) any Stockholder acquires the right to vote or share in the voting of any Company Shares, the terms “Owned Shares”
and “Covered Shares” shall be deemed to refer to and include such Company Shares as well as all such stock dividends
and distributions and any securities into which or for which any or all of such Company Shares may be changed or exchanged or which are
received in such transaction.

 

10.           Amendment
and Modification. This Agreement may not be amended, modified or supplemented in any manner, whether by course of conduct or otherwise,
except by an instrument in writing signed by Acquiror and the applicable Stockholder.

 

11.           Waiver.
No failure or delay by any party hereto in exercising any right, power or privilege hereunder shall operate as a waiver thereof nor shall
any single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any other right, power or privilege.
The rights and remedies of the parties hereto hereunder are cumulative and are not exclusive of any rights or remedies which they would
otherwise have hereunder. Any agreement on the part of a party hereto to any such waiver shall be valid only if set forth in a written
instrument executed and delivered by such party.

 

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12.          Notices.
All notices and other communications under this Agreement between or among the parties shall be in writing and shall be deemed to have
been duly given, delivered and received (a) when delivered in person, (b) when delivered after posting in the U.S. mail, having
been sent registered or certified mail, return receipt requested, postage prepaid, (c) when delivered by FedEx or other nationally
recognized overnight delivery service or (d) when delivered by email (provided that, if receipt has not been confirmed (excluding
any automated reply, such as an out-of-office notification) then a copy shall be dispatched in the manner described in the preceding clause
(c) no later than 24 hours after such delivery by email), addressed as follows:

 

If to Acquiror, to:

 

AMCI Acquisition Corp. II

600 Steamboat Road

Greenwich, Connecticut 06830

Attn:     Nimesh Patel

E-mail:   [***]

 

with a copy (which shall not constitute notice) to:

 

White & Case LLP

1221 Avenue of the Americas

New York, NY 10020-1095

Attn:     Emery Choi, Oliver Wright and Elliott Smith

E-mail:   [***], [***] and [***]

 

If to a Stockholder, to the address or
email address set forth on such Stockholder’s signature page hereto,

 

or to such other address(es) or email address(es)
as the Parties may from time to time designate in writing. Copies delivered solely to outside counsel shall not constitute notice.

 

13.          No
Ownership Interest. Nothing contained in this Agreement shall be deemed to vest in Acquiror any direct or indirect ownership of or
with respect to the Covered Shares of a Stockholder. All rights, ownership and economic benefits of and relating to the Covered Shares
of a Stockholder shall remain vested in and belonging to such Stockholder in the voting or disposition of any such Stockholder’s
Covered Shares except as otherwise provided herein.

 

14.          Entire
Agreement. This Agreement and the Merger Agreement constitute the entire agreement, and supersede all prior agreements and
understandings, both written and oral, between the parties hereto with respect to the subject matter hereof and thereof. This Agreement
shall not be effective or binding upon the Stockholder until after such time as the Merger Agreement is executed and delivered by the
Company, Acquiror and Merger Sub.

 

15.          No
Third-Party Beneficiaries. Each Stockholder hereby agrees that his, her or its representations, warranties and covenants set forth
herein are solely for the benefit of Acquiror in accordance with and subject to the terms of this Agreement, and this Agreement is not
intended to, and does not, confer upon any Person, other than the parties hereto, any rights or remedies hereunder, including the right
to rely upon the representations and warranties set forth herein, and the parties hereto hereby further agree that this Agreement may
only be enforced against, and any Action that may be based upon, arise out of or relate to this Agreement, or the negotiation, execution
or performance of this Agreement may only be made against, the Persons expressly named as parties hereto; provided that the Company
shall be an express third party beneficiary with respect to Section 5 and Section 6(b).

 

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16.          Governing
Law and Venue; Service of Process; Waiver of Jury Trial.

 

(a)             This
Agreement, and all claims or causes of action based upon, arising out of, or related to this Agreement or the transactions contemplated
hereby (whether based on contract, tort, equity or otherwise), shall be governed by, and construed in accordance with, the Laws of the
State of Delaware, without giving effect to principles or rules of conflict of laws (whether of the State of Delaware or of any other
jurisdiction) to the extent such principles or rules would require or permit the application of Laws of another jurisdiction.

 

(b)             Any
Action based upon, arising out of or related to this Agreement, or the transactions contemplated hereby, shall be brought in the Court
of Chancery of the State of Delaware (or, to the extent such court does not have subject matter jurisdiction, the Superior Court of the
State of Delaware), or, if it has or can acquire jurisdiction, in the United States District Court for the District of Delaware, and each
of the parties irrevocably (i) submits to the exclusive jurisdiction of each such court in any such Action, (ii) waives any
objection he, she or it may now or hereafter have to personal jurisdiction, venue or to convenience of forum, agrees that all claims in
respect of the Action shall be heard and determined only in any such court, (iii) agrees that all claims in respect of such Action
shall be heard and determined only in any such court and (iv) agrees not to bring any Action arising out of or relating to this Agreement
or the transactions contemplated hereby in any other court. Nothing herein contained shall be deemed to affect the right of any party
to serve process in any manner permitted by Law, or to commence Actions or otherwise proceed against any other party in any other jurisdiction,
in each case, to enforce judgments obtained in any Action brought pursuant to this Section 16.

 

(c)             EACH
PARTY ACKNOWLEDGES AND AGREES THAT ANY CONTROVERSY WHICH MAY ARISE UNDER THIS AGREEMENT AND THE TRANSACTIONS CONTEMPLATED HEREBY
IS LIKELY TO INVOLVE COMPLICATED AND DIFFICULT ISSUES, AND THEREFORE EACH PARTY HEREBY IRREVOCABLY, UNCONDITIONALLY AND VOLUNTARILY WAIVES
ANY RIGHT SUCH PARTY MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY ACTION, SUIT OR PROCEEDING DIRECTLY OR INDIRECTLY ARISING OUT
OF OR RELATING TO THIS AGREEMENT OR ANY OF THE TRANSACTIONS CONTEMPLATED HEREBY.

 

17.           Assignment;
Successors. Neither this Agreement nor any of the rights, interests or obligations hereunder shall (a) be assigned by any of
the Stockholders in whole or in part (whether by operation of Law or otherwise) without the prior written consent of Acquiror or (b) be
assigned by Acquiror in whole or in part (whether by operation of Law or otherwise) without the prior written consent of the applicable
Stockholder. Any such assignment without such consent shall be null and void. This Agreement shall be binding upon, inure to the benefit
of and be enforceable by the parties hereto and their respective heirs, successors and permitted assigns.

 

18.           Enforcement.
The rights and remedies of the parties shall be cumulative with and not exclusive of any other remedy conferred hereby. The parties agree
that irreparable damage would occur in the event that any of the provisions of this Agreement were not performed in accordance with their
specific terms or were otherwise breached. It is accordingly agreed that the parties shall be entitled to an injunction or injunctions
to prevent breaches of this Agreement and to specific enforcement of the terms and provisions of this Agreement, in addition to any other
remedy to which any party is entitled at law or in equity. In the event that any Action shall be brought in equity to enforce the provisions
of this Agreement, no party shall allege, and each party hereby waives the defense, that there is an adequate remedy at law, and each
party hereby waives any requirement for the securing or posting of any bond in connection therewith.

 

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19.           Grant
of Irrevocable Proxy. Each Stockholder hereby irrevocably grants and appoints Acquiror and any designee of Acquiror, and each of them
individually, as his, her or its proxy and attorney-in-fact, with full power of substitution and resubstitution, to the fullest extent
of such Stockholder’s rights with respect to the Covered Shares, effective as of the date hereof and continuing until the termination
of this Agreement pursuant to Section 4 (the “Voting Period”), to vote (or execute written consents, if
applicable) with respect to the Covered Shares as required pursuant to, and for the sole purposes of voting in accordance with, and solely
with respect to the matters set forth in, Section 1, in each case to the same extent and with the same effect as such Stockholder
might or could do under applicable Law. The proxy granted by each Stockholder hereunder shall be irrevocable during the Voting Period,
shall be deemed to be coupled with an interest sufficient in Law to support an irrevocable proxy, and each Stockholder (a) will take
such further action or execute such other instruments as may be necessary to effectuate the intent of this proxy and (b) hereby revokes
any proxy previously granted by such Stockholder with respect to any Covered Shares (but only with respect to the matters set forth in
Section 1 and only during the Voting Period). The power of attorney granted by each Stockholder hereunder is a durable power
of attorney and shall survive the bankruptcy or dissolution of such Stockholder. Other than as provided in this Section 19,
during the Voting Period, no Stockholder shall directly or indirectly grant any Person any proxy (revocable or irrevocable), power of
attorney or other authorization with respect to any of such Stockholder’s Covered Shares in connection with the matters set forth
in Section 1.

 

20.           Severability.
Whenever possible, each provision of this Agreement shall be interpreted in such a manner as to be valid and enforceable under applicable
Law, but, if any provision of this Agreement is held invalid or unenforceable by any court of competent jurisdiction, the other provisions
of this Agreement shall remain in full force and effect. If any provision contained herein is, to any extent, held invalid or unenforceable
in any respect under the Laws governing this Agreement, the parties shall take any actions necessary to render the remaining provisions
of this Agreement valid and enforceable to the fullest extent permitted by Law and, to the extent necessary, shall amend or otherwise
modify this Agreement to replace any provision contained herein that is held invalid or unenforceable with a valid and enforceable provision
giving effect to the intent of the parties.

 

21.           Counterparts.
This Agreement may be executed in any number of counterparts, each of which shall be deemed an original, but all of which together shall
constitute one and the same instrument. Delivery of an executed counterpart of a signature page to this Agreement by facsimile, e-mail,
or scanned pages shall be effective as delivery of a manually executed counterpart to this Agreement.

 

22.           Directors
and Officers. Notwithstanding any provision of this Agreement to the contrary, nothing in this Agreement shall limit or restrict any
Stockholder, or a designee of such Stockholder, who is a director or officer of the Company from acting in such capacity or fulfilling
the obligations of such office, including by voting, in his or her capacity as a director of the Company, in the Stockholder’s,
or his, her or its designee’s, sole discretion on any matter (it being understood that this Agreement shall apply to the Stockholder
solely in the Stockholder’s capacity as a holder of the Covered Shares). In this regard, the Stockholder shall not be deemed to
make any agreement or understanding in this Agreement in the Stockholder’s capacity as a director or officer of the Company.

 

[The remainder of this page is
intentionally left blank.]

 

    	 	9	 

     

    

 

IN WITNESS WHEREOF, the parties
have executed this Agreement as of the date first written above.

 

	 	AMCI ACQUISITION CORP. II
	 	 
	 	By:	 
	 	 	Name: [●]
	 	 	Title: [●]

 

[Signature Page to Company Stockholder
Support Agreement]

 

    	 	10	 

     

    

 

 

 

	 	STOCKHOLDER
	 	 
	 	Name of
    Stockholder:
	 	 
	 	[●]
	 	 
	 	 
	 	Signature:	 
	 	 
	 	If signed on
    behalf of an entity, include the following:
	 	Name:
	 	Title:
	 	 
	 	In all cases, include
    the following:
	 	 
	 	Address for Notice:
       
	 	[●]
	 	 
	 	 
	 	 
	 	 
	 	 
	 	Email for Notice:
       
	 	[●]

 

[Signature Page to Company Stockholder
Support Agreement]

 

     

     

    

 

Exhibit A

 

[Omitted.]Exhibit 10.4

 

SPONSOR SUPPORT AGREEMENT

 

This Sponsor Support Agreement
(this “Agreement”) is entered into on March 8, 2022, by and among AMCI Sponsor II LLC, a Delaware limited liability
company (the “Sponsor”), AMCI Acquisition Corp. II, a Delaware corporation (“Acquiror”), LanzaTech
NZ Inc., a Delaware corporation (the “Company”), and the Persons identified on Schedule I attached hereto (together
with the Sponsor, the “Insider Holders”). Acquiror, the Insider Holders and the Company are sometimes collectively
referred to herein as the “Parties,” and each of them is sometimes individually referred to herein as a “Party.”
Certain terms used in this Agreement have the applicable meanings ascribed to them in Section 3.1.

 

RECITALS

 

WHEREAS, contemporaneously
with the Parties’ execution and delivery of this Agreement, Acquiror, Merger Sub and the Company have entered into an Agreement
and Plan of Merger, dated as of the date hereof (as amended, restated, supplemented or otherwise modified from time to time, the “Merger
Agreement”), pursuant to which, among other things, Merger Sub will merge with and into the Company, with the Company continuing
as the surviving corporation in the Merger and as a wholly owned Subsidiary of Acquiror;

 

WHEREAS, as of the date hereof,
the Insider Holders are collectively the holders of record and the beneficial owners (within the meaning of Rule 13d-3 promulgated
under the Exchange Act) of (a) 3,750,000 shares of Class B common stock, par value $0.0001 per share, of Acquiror (the “Owned
Shares”) and (b) warrants to purchase 3,500,000 shares of Class A common stock, par value $0.0001 per share, of Acquiror,
at an exercise price of $11.50 per share and issued to the Sponsor substantially concurrently with Acquiror’s initial public offering
(the “Private Placement Warrants”); and

 

WHEREAS, as an inducement to
the willingness of Acquiror and the Company to enter into the Merger Agreement and to consummate the transactions contemplated thereby,
the Parties desire to agree to certain matters as set forth herein.

 

AGREEMENT

 

NOW, THEREFORE, in consideration
of the foregoing and the representations, warranties, covenants and agreements set forth herein, the Parties, intending to be legally
bound, hereby agree as follows:

 

ARTICLE I

COVENANTS AND AGREEMENTS

 

Section 1.1         Redemption
Related Forfeiture. Each Insider Holder hereby agrees that, if any Acquiror Share Redemptions occur and the Redemption Percentage
resulting therefrom is more than 50%, then immediately prior to the Closing, subject only to the occurrence of the Closing, such number
of Promote Shares (rounded down to the nearest whole share) equal to the applicable Forfeited Promote Shares shall be forfeited by the
Insider Holders, with each Insider Holder having forfeited such Insider Holder’s Promote Shares Pro Rata Percentage of the Forfeited
Promote Shares. Acquiror shall be authorized, and each Insider Holder hereby authorizes Acquiror to, on behalf of each such Insider Holder,
deem surrendered, forfeited and transferred, and to take all actions as may be necessary to cancel, such Insider Holder’s Forfeited
Promote Shares, and each such Insider Holder shall take any action reasonably necessary or reasonably requested by Acquiror, in each
case to allow Acquiror to effect such forfeiture of the applicable Forfeited Promote Shares. For the avoidance of doubt, if the Redemption
Percentage is 50% or less, no forfeiture of the Promote Shares shall be effected pursuant to this Section 1.1.

 

     

     

    

 

Section 1.2         Restrictions
on Transfer.

 

(a)        From
the date hereof until the earlier of (i) the Closing and (ii) the valid termination of this Agreement pursuant to Section 3.3,
no Insider Holder (and any other Person to which any Covered Security is Transferred) shall, directly or indirectly, Transfer any of
the Covered Securities legally or beneficially owned by him, her or it, other than in accordance with Section 1.3. In the
event that any Insider Holder (or any other Person to which any Covered Security is Transferred) Transfers any Covered Security prior
to the Closing, Acquiror shall amend Schedule I hereto promptly thereafter (and, in any event, prior to the Closing) to reflect
such Transfer.

 

(b)        The
Parties acknowledge and agree that (i) notwithstanding anything to the contrary herein, all Covered Securities beneficially owned
by any Insider Holder (or any Person to which any Covered Security is Transferred) will remain subject to any restrictions on Transfer
under all applicable securities laws and all rules and regulations promulgated thereunder, and (ii) any purported Transfer
of any Covered Security in violation of this Agreement will be null and void ab initio.

 

Section 1.3         Exceptions
to Restrictions on Transfer. Notwithstanding anything to the contrary in Section 1.2(a), each Insider Holder will be
permitted to Transfer Promote Shares or Private Placement Warrants:

 

(a)        to
any of Acquiror’s officers or directors, any trust whose sole beneficiaries are the family members of an officer or director of
Acquiror, or any family member of any of Acquiror’s officers or directors, any affiliate of the Sponsor or to any members of the
Sponsor;

 

(b)        in
the case of an individual, by gift to a member of such individual’s immediate family or to a trust, the beneficiary of which is
a member of such individual’s immediate family, or to a charitable organization;

 

(c)        in
the case of an individual, by virtue of laws of descent and distribution upon death of such individual;

 

(d)        in
the case of an individual, pursuant to a qualified domestic relations order; or

 

(e)        by
virtue of the laws of the State of Delaware or the Sponsor’s limited liability company agreement upon dissolution of the Insider
Holder;

 

provided,
however, that in the case of any of the foregoing clauses (a) through (e), these permitted Transferees must sign a counterpart
to this Agreement becoming bound by all the terms set forth herein and enter into a written agreement with Acquiror agreeing to be bound
by the transfer restrictions contained in the Letter Agreement and the other restrictions contained therein. For clarity, at the Closing,
each Insider Holder will be permitted to Transfer, or otherwise forfeit in lieu of such Transfer, such number of Promote Shares as are
required to be Transferred by such Insider Holder pursuant to the Anchor Investor Letter Agreements or the Non-Redemption Agreements,
as the case may be; provided that such Transfer or forfeiture shall not conflict with such Insider Holder’s obligations
pursuant to Section 1.1.

 

    	 	2	 

     

    

 

Section 1.4         Sponsor
Support Agreement.

 

(a)        Subject
to the earlier termination of this Agreement in accordance with Section 3.3, each Insider Holder, solely in such Person’s
capacity as a stockholder of Acquiror, irrevocably and unconditionally agrees in respect of all of the Insider Holder’s Covered
Securities, that, at the Acquiror Stockholders’ Meeting or any other meeting of the stockholders of Acquiror (whether annual or
special and whether or not an adjourned or postponed meeting, however called and including any adjournment or postponement thereof),
and in connection with any written consent of stockholders of Acquiror, such Insider Holder shall:

 

(i)        when
such meeting is held, appear at such meeting or otherwise cause such Insider Holder’s Covered Securities to be counted as present
thereat for purposes of establishing a quorum;

 

(ii)        vote
(or validly execute and return an action by written consent), or cause to be voted at such meeting (or validly execute and return and
cause such consent to be granted with respect to), all of such Insider Holder’s Covered Securities owned as of the record date
for such meeting (or the date that any written consent is executed by such Insider Holder) in favor of each of the Transaction Proposals
and each other matter required (or reasonably requested by the Company or Acquiror) to be approved or adopted by the stockholders of
Acquiror in order to effect each of the Transaction Proposals; and

 

(iii)        vote
(or validly execute and return an action by written consent), or cause to be voted at such meeting (or validly execute and return and
cause such consent to be granted with respect to), all of such Insider Holder’s Covered Securities against (A) any Business
Combination Proposal and (B) any other action that would reasonably be expected to (1) materially impede, interfere with, delay,
postpone or adversely affect the Merger or any of the other transactions contemplated by the Merger Agreement, (2) to the knowledge
of such Insider Holder, result in a material breach of any covenant, representation or warranty or other obligation or agreement of Acquiror
under the Merger Agreement or (3) result in a material breach of any covenant, representation or warranty or other obligation or
agreement of such Insider Holder contained in this Agreement.

 

The obligations of each Insider Holder specified
in this Section 1.4(a) shall apply whether or not any of the Transaction Proposals is recommended by the Acquiror Board
and whether or not the Acquiror Board has previously recommended any of the Transaction Proposals but changed such recommendation.

 

(b)        From
the date hereof until the earlier of (i) the Closing or (ii) the valid termination of this Agreement pursuant to Section 3.3,
each Insider Holder will comply with and fully perform all of its covenants and agreements set forth in the Letter Agreement, and each
Insider Holder shall not amend, restate, supplement or otherwise modify, or cause Acquiror to amend, restate, supplement or otherwise
modify or waive, any provision of the Letter Agreement without the prior written consent of the Company other than as provided herein.

 

Section 1.5         No
Inconsistent Agreement. Each Insider Holder hereby covenants and agrees that such Insider Holder shall not, at any time prior to
the termination of this Agreement pursuant to Section 3.3, (a) enter into any voting agreement or voting trust with
respect to any of such Insider Holder’s Covered Securities that is inconsistent with such Insider Holder’s obligations pursuant
to this Agreement, (b) grant a proxy or power of attorney with respect to any of such Insider Holder’s Covered Shares that
is inconsistent with such Insider Holder’s obligations pursuant to this Agreement or (c) enter into any Contract or undertaking
that is otherwise inconsistent with, or would interfere with, or prohibit or prevent him, her or it from satisfying, his, her or its
obligations pursuant to this Agreement.

 

    	 	3	 

     

    

 

Section 1.6         Disclosure.
Each Insider Holder hereby authorizes each of the Company and Acquiror to publish and disclose, in any announcement, filing or disclosure
required to be made by any Governmental Order or other applicable Law or the rules of any national securities exchange or as requested
by the SEC, such Insider Holder’s identity and ownership of Covered Securities and such Insider Holder’s obligations under
this Agreement. No Insider Holder nor any of his, her or its Affiliates (other than Acquiror) shall issue any press release or make any
other public announcement or public statement with respect to this Agreement, the Merger Agreement or any of the transactions contemplated
hereby or thereby (each, a “Public Communication”), without the prior written consent of Acquiror and the Company
(which consent may be withheld in Acquiror’s or the Company’s sole discretion), except (a) as required by applicable
Law or any Governmental Authority of competent jurisdiction (including pursuant to any court process), in which case the Insider Holder
shall provide each of Acquiror and the Company and their respective legal counsel with a reasonable opportunity to review and comment
on such Public Communication (solely with respect to such portions that relate to this Agreement, the Merger Agreement or the transactions
contemplated hereby or thereby) in advance of its issuance and shall give reasonable and good faith consideration to any such comments
or (b) with respect to a Public Communication that is consistent with prior disclosures by Acquiror and the Company; provided that
the foregoing shall not apply to any disclosure required to be made by such Insider Holder to a Governmental Authority so long as such
disclosure is consistent with the terms of this Agreement and the Merger Agreement and the disclosures made by the Company and Acquiror
pursuant to the terms of the Merger Agreement.

 

Section 1.7         Non-Solicitation.
From the date hereof until the earlier of (a) the Closing or (b) the valid termination of this Agreement pursuant to Section 3.3,
no Insider Holder shall, and each Insider Holder shall cause his, her or its controlled Affiliates not to, and shall use reasonable best
efforts to cause his, her or its and their Representatives not to, (i) approve, endorse, recommend or make any proposal or offer
that constitutes a Business Combination Proposal, (ii) initiate, solicit, enter into or continue discussions, negotiations or transactions
with, or respond to any inquiries or proposals by, any Person with respect to, a Business Combination Proposal (other than to inform
such Person of the Insider Holder’s obligations pursuant to this Section 1.7), (iii) enter into any acquisition
agreement, business combination agreement, merger agreement or similar definitive agreement, or any letter of intent, memorandum of understanding
or agreement in principle, or any other agreement relating to a Business Combination Proposal, in each case, other than to or with the
Company and its Representatives, (iv) otherwise knowingly encourage or facilitate any such inquiries, proposals, discussions, or
negotiations or (v) resolve or agree to do any of the foregoing. Each Insider Holder also agrees that immediately following the
execution of this Agreement he, she or it shall, and shall instruct each of his, her or its Representatives, its Affiliates and their
respective Representatives to, immediately cease and terminate all discussions and negotiations with any Persons that may be ongoing
with respect to a Business Combination Proposal (other than the Company and its Representatives).

 

Notwithstanding anything in
this Agreement to the contrary, (x) each Insider Holder shall not be responsible for the actions of Acquiror or the Acquiror Board
(or any committee thereof), any Subsidiary of Acquiror, or any officers, directors (in their capacity as such), employees and professional
advisors of any of the foregoing (collectively, the “Acquiror Related Parties”), (y) each Insider Holder makes
no representations or warranties with respect to the actions of any of the Acquiror Related Parties and (z) any breach by Acquiror
of its obligations under Section 8.4 of the Merger Agreement shall not in itself be considered a breach of this Section 1.7 (it
being understood that, for the avoidance of doubt, such Stockholder shall remain responsible for his, her or its breach of this Section 1.7
or any breach of this Section 1.7 by his, her or its Representatives (other than any such Representative that is
acting in its capacity as an Acquiror Related Party)).

 

    	 	4	 

     

    

 

Section 1.8         Waivers.

 

(a)        Each
Insider Holder hereby irrevocably waives (for himself, herself or itself and for his, her or its successors, heirs and assigns), to the
fullest extent permitted by applicable Law and the Governing Documents of Acquiror, and agrees not to assert or perfect, any rights to
adjustment, anti-dilution or other protection or right with respect to the Acquiror Class B Shares that would result in the Acquiror
Class B Shares converting into any other Acquiror Common Share in connection with any of the transactions contemplated by the Merger
Agreement or any Ancillary Agreement (including the PIPE Investment and the Merger) at a ratio greater than one-for-one (including the
provisions of Section 4.3(b) of Acquiror’s Amended and Restated Certificate of Incorporation). The waiver specified in
this Section 1.8(a) will be applicable only in connection with the transactions contemplated by the Merger Agreement
or any Ancillary Agreement (or any issuance of Equity Securities of Acquiror issued in connection with the transactions contemplated
by the Merger Agreement or any Ancillary Agreement) and will be void and of no force and effect if the Merger Agreement is validly terminated
for any reason prior to the Closing.

 

(b)        Each
Insider Holder hereby irrevocably and unconditionally agrees not to elect to redeem any Acquiror Common Share in an Acquiror Share Redemption
or otherwise.

 

ARTICLE II

REPRESENTATIONS AND WARRANTIES

 

Section 2.1         Representations
and Warranties of the Insider Holders. Each Insider Holder represents and warrants to Acquiror and the Company as follows:

 

(a)        Organization;
Due Authorization. If such Insider Holder is not an individual, it is duly organized, validly existing and in good standing under
the Laws of the jurisdiction in which it is incorporated, formed, organized or constituted, and the execution, delivery and performance
of this Agreement and the consummation of the transactions contemplated hereby are within such Insider Holder’s corporate or other
organizational powers and have been duly authorized by all necessary corporate or other organizational actions on the part of such Insider
Holder. If such Insider Holder is an individual, such Insider Holder has full legal capacity, right and authority to execute, deliver
and perform this Agreement and to consummate the transactions contemplated hereby. This Agreement has been duly executed and delivered
by such Insider Holder and, assuming due authorization, execution and delivery by the other Parties, this Agreement constitutes a legally
valid and binding obligation of such Insider Holder, enforceable against such Insider Holder in accordance with the terms hereof (except
as enforceability may be limited by bankruptcy Laws, other similar Laws affecting creditors’ rights and general principles of equity
affecting the availability of specific performance and other equitable remedies). If this Agreement is being executed in a representative
or fiduciary capacity, the Person signing this Agreement has full power and authority to enter into this Agreement on behalf of the applicable
Insider Holder.

 

(b)        Ownership.
As of the date hereof, such Insider Holder is the sole holder of record and beneficial owner (within the meaning of Rule 13d-3 promulgated
under the Exchange Act) of, and has good title to, the number of Acquiror Common Shares and the number of Private Placement Warrants
set forth opposite such Insider Holder’s name in the columns titled “Acquiror Common Shares” and “Private Placement
Warrants,” respectively, in Schedule I hereto (such Acquiror Common Shares and such Private Placement Warrants, collectively,
such Insider Holder’s “Owned Securities”). As of the date hereof, such Insider Holder does not own of record
or beneficially (or have any right, option or warrant to acquire) any Equity Security of Acquiror (or any indebtedness convertible into
or exercisable or exchangeable for any Equity Security of Acquiror), other than such Insider Holder’s Owned Securities. As of the
date hereof, and except as provided in this Agreement, Acquiror’s Governing Documents, the Merger Agreement, the Letter Agreement,
the Anchor Investor Letter Agreements or applicable securities Laws, such Insider Holder (i) has full voting power, full power of
disposition and full power to issue instructions with respect to the matters set forth herein with respect to such Insider Holder’s
Covered Securities, (ii) has not entered into any voting agreement or voting trust, and has no knowledge and is not aware of any
such voting agreement or voting trust in effect, with respect to any of such Insider Holder’s Covered Securities that is inconsistent
with such Insider Holder’s obligations pursuant to this Agreement, (iii) has not granted a proxy or power of attorney with
respect to any of such Insider Holder’s Covered Securities that is inconsistent with such Insider Holder’s obligations pursuant
to this Agreement, and has no knowledge and is not aware of any such proxy or power of attorney in effect, and (iv) has not entered
into any Contract or undertaking that is otherwise inconsistent with, or would interfere with, or prohibit or prevent him, her or it
from satisfying, his, her or its obligations pursuant to this Agreement and has no knowledge and is not aware of any such Contract or
undertaking.

 

    	 	5	 

     

    

 

(c)        Governmental
Authorizations. Other than the filings, notices and reports pursuant to, in compliance with or required to be made under the Exchange
Act, no filings, notices, reports, consents, registrations, approvals, permits, waivers, expirations of waiting periods or authorizations
are required to be obtained by such Insider Holder from, or to be given by such Insider Holder to, or be made by such Insider Holder
with, any Governmental Authority in connection with the execution, delivery and performance by such Insider Holder of this Agreement,
the consummation of the transactions contemplated hereby or the Merger or the other transactions contemplated by the Merger Agreement.

 

(d)        No
Conflicts. The execution and delivery of this Agreement by such Insider Holder does not, and the performance by such Insider Holder
of its obligations hereunder will not, (i) if such Insider Holder is not an individual, conflict with or result in a violation of
the Governing Documents of such Insider Holder, (ii) with or without notice, lapse of time or both, constitute or result in a breach
or violation of, a termination (or right of termination) of or a default under, the loss of any benefit under, or the creation, modification
or acceleration of any obligations under, any Contract binding upon such Insider Holder (including the Anchor Investor Letter Agreements),
in each case in a manner that would reasonably be expected to prevent or materially delay or materially impair such Insider Holder’s
ability to perform his, her or its obligations hereunder or to consummate the transactions contemplated by this Agreement, the consummation
of the Merger or any other transaction contemplated by the Merger Agreement, or (iii) conflict with or violate any Law to which
such Insider Holder is subject, (iv) require any consent, approval or authorization of, declaration, filing or registration with,
or notice to, any Person, in each case the absence of which would reasonably be expected to prevent or materially delay or materially
impair such Insider Holder’s ability to perform his, her or its obligations hereunder or to consummate the transactions contemplated
by this Agreement, the consummation of the Merger or any other transaction contemplated by the Merger Agreement, or (v) constitute
or result in the creation of any Lien on such Insider Holder’s Covered Securities, except for any Lien under applicable securities
Laws.

 

(e)        Litigation.
There is no Action pending against such Insider Holder or, to the knowledge of such Insider Holder, threatened against such Insider Holder,
and such Insider Holder is not a party to or subject to the provisions of any Governmental Order, in each case, that challenges all or
any part of this Agreement or any of the transactions contemplated hereby, or that seeks to, or would reasonably be expected to, prevent,
enjoin or materially delay the performance by such Insider Holder of its, his or her obligations under this Agreement.

 

(f)        Brokerage
Fees. Except as disclosed in Section 6.15 of the Acquiror Disclosure Letter, no financial advisor, investment banker, broker,
finder or other similar intermediary is entitled to any fee or commission in connection with the Merger Agreement, this Agreement or
any other Ancillary Agreement, or any of the transactions contemplated hereby or thereby, in each case, based upon any agreement or arrangement
made by, or, to the knowledge of such Insider Holder, on behalf of, such Insider Holder for which Acquiror, the Company or any of the
Company’s Subsidiaries would have any obligation.

 

    	 	6	 

     

    

 

(g)        Affiliate
Arrangements. Except as disclosed in the prospectus, dated August 3, 2021, filed in connection with Acquiror’s initial
public offering, neither any Insider Holder nor any of its Affiliates or any member of its immediate family (i) is party to, or
has any rights with respect to or arising from, any material Contract with Acquiror or any of its Subsidiaries or (ii) is (or will
be) entitled to receive from Acquiror, the Company or any of their respective Subsidiaries any finder’s fee, reimbursement, consulting
fee, monies or consideration in the form of equity in respect of any repayment of a loan or other compensation prior to, or in connection
with, any services rendered in order to effectuate the consummation of Acquiror’s initial Business Combination (regardless of the
type or form of such transaction, but including, for the avoidance of doubt, the Merger).

 

(h)        Acknowledgment.
Such Insider Holder has read this Agreement and has had the opportunity to consult with its tax, legal and other advisors regarding this
Agreement and the transactions contemplated hereby.

 

ARTICLE III

MISCELLANEOUS

 

Section 3.1         Definitions.

 

(a)        Capitalized
terms used and not otherwise defined herein shall have the respective meanings ascribed to such terms in the Merger Agreement.

 

(b)        As
used in this Agreement, the following terms shall have the following meanings:

 

“Acquiror”
has the meaning set forth in the preamble hereto.

 

“Agreement”
has the meaning set forth in the preamble hereto.

 

“Anchor
Investor Letter Agreements” means the agreements entered into by and among Nimesh Patel, Brian Beem, Patrick Murphy, Hans Mende,
AMCI Group, LLC Series 35 and certain anchor investors relating to an expression of interest by such anchor investors to acquire
certain Acquiror Common Shares.

 

“Company”
has the meaning set forth in the preamble hereto.

 

“Covered
Securities” means, with respect to any Insider Holder, (i) all of such Insider Holder’s Owned Securities and (ii) all
other Equity Securities of Acquiror of which such Insider Holder acquires beneficial ownership (whether pursuant to any dividend, distribution,
combination, split, subdivision, conversion, exchange, transfer, sale, cancelation, repurchase, redemption, reclassification or other
change to, or transaction in, any Equity Security or otherwise), after the date hereof but before the Closing.

 

“Forfeited
Promote Shares” means a number of the Promote Shares equal to the product of (i) one third (1/3)
of the Promote Shares multiplied by (ii) a percentage equal to the product of (A) (1) the Redemption Percentage minus
50% multiplied by (B) two (2). An illustrative example setting forth the calculation of the Forfeited Promote Shares
is set forth on Exhibit A attached hereto.

 

“immediate
family” has the meaning ascribed to such term in Rule 16a-1 promulgated under the Exchange Act.

 

    	 	7	 

     

    

 

“Letter
Agreement” means the agreement entered into by and between Acquiror, Evercore Group L.L.C., as representatives of the several
underwriters, Sponsor, AMCI Group, LLC Series 35 and certain officers and directors of Acquiror, dated as of August 3, 2021,
relating to the underwriting of Acquiror’s initial public offering.

 

“Merger
Agreement” has the meaning set forth in the recitals hereto.

 

“Owned
Securities” has the meaning set forth in Section 2.1(b).

 

“Owned
Shares” has the meaning set forth in the recitals hereto.

 

“Parties”
and “Party” have the meaning set forth in the recitals hereto.

 

“Private
Placement Warrants” has the meaning set forth in the recitals hereto.

 

“Promote
Shares” means the Owned Shares (of which 3,750,000 shares are outstanding) or any other Equity Securities of Acquiror into
which such Owned Shares are converted.

 

“Promote
Shares Pro Rata Percentage” means, with respect to any Insider Holder, the percentage set forth opposite such Insider Holder’s
name in the column titled “Promote Shares Pro Rata Percentage” on Schedule I (as it may be amended from time to time
prior to the Closing).

 

“Public
Communication” has the meaning set forth in Section 1.6.

 

“Redemption
Percentage” means the percentage calculated as the quotient (expressed as a percentage) of (i) the aggregate number of
Acquiror Class A Shares that are the subject of Acquiror Share Redemptions (that are not withdrawn) divided by (ii) the
total number of issued and outstanding Acquiror Class A Shares immediately prior to the Effective Time and without giving effect
to any such Acquiror Share Redemption.

 

“Sponsor”
has the meaning set forth in the preamble.

 

“Transfer”
means the (i) sale of, assignment, exchange, conveyance, offer to sell, contract or agreement to sell, hypothecate, pledge, grant
of any option to purchase or otherwise dispose of or agreement to dispose of, or other transfer or disposition, whether direct or indirect,
whether or not for value, and whether or not by operation of law (including by merger, consolidation or otherwise), including any transfer
of a Covered Security to a broker or other nominee (with or without a corresponding change in beneficial ownership) and any transfer
of voting control of such Covered Security, (ii) establishment or increase of a put equivalent position or liquidation with respect
to or decrease of a call equivalent position within the meaning of Section 16 of the Exchange Act and the rules and regulations
of the SEC promulgated thereunder with respect to, any security, (iii) entry into any swap or other arrangement that transfers to
another, in whole or in part, any of the economic consequences of ownership of any security, whether any such transaction is to be settled
by delivery of such securities, in cash or otherwise, (iv) entry into any Contract providing for any transaction contemplated by
the preceding clauses (i) through (iii), or (v) public announcement of any intention to effect any transaction specified in
clauses (i) through (iv).

 

Section 3.2         Construction.
This Agreement and all of its provisions shall be interpreted in accordance with Section 1.2 of the Merger Agreement, the provisions
of which are incorporated herein by reference as if set forth herein, mutatis mutandis.

 

    	 	8	 

     

    

 

Section 3.3         Termination.
This Agreement and all of its provisions shall automatically terminate and be of no further force or effect (a) upon the termination
of the Merger Agreement in accordance with its terms or (b) as mutually agreed in writing by the Parties in accordance with Section 3.5.
Upon any valid termination of this Agreement, all obligations of the Parties hereunder shall terminate, without any Liability or other
obligation on the part of any Party to any Person in respect of this Agreement or the transactions contemplated hereby, and no Person
shall have any claim or right against any Party, whether in contract, tort or otherwise, with respect to the subject matter hereof; provided,
however, that the termination of this Agreement shall not relieve any Party from any Liability arising in respect of any breach
of this Agreement prior to such termination. This Article III shall survive the termination of this Agreement.

 

Section 3.4         Assignment.
Neither this Agreement nor any of the rights, interests or obligations hereunder shall (a) be assigned by any of the Insider Holders
in whole or in part (whether by operation of Law or otherwise) without the prior written consent of Acquiror and the Company or (b) be
assigned by Acquiror or the Company in whole or in part (whether by operation of Law or otherwise) without the prior written consent
of the Company or the Acquiror, respectively, and the applicable Insider Holder. Any such assignment without such consent shall be null
and void. This Agreement shall be binding upon, inure to the benefit of and be enforceable by the parties hereto and their respective
heirs, successors and permitted assigns.

 

Section 3.5         Amendment.
Subject to Section 3.3, this Agreement may not be amended, restated, supplemented or otherwise modified, except upon the
execution and delivery of a written agreement providing therefor by Acquiror, the Company, each Insider Holder and any other Person to
which any Owned Share or Private Placement Warrant has been Transferred in accordance with Section 1.2 and Section 1.3.

 

Section 3.6         Waiver.
No failure or delay by any Party in exercising any right, power or privilege hereunder shall operate as a waiver thereof, nor shall any
single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any other right, power or privilege.
The rights and remedies of the Parties hereunder are cumulative and are not exclusive of any rights or remedies otherwise available to
the Parties. No waiver of any right, power or privilege hereunder shall be valid unless it is set forth in a written instrument executed
and delivered by the Party to be charged with such waiver.

 

Section 3.7         No
Third-Party Beneficiaries. Nothing expressed or implied in this Agreement is intended or shall be construed to confer upon or give
any Person, other than the Parties and their respective heirs, successors and permitted assigns, any right or remedy under or by reason
of this Agreement.

 

Section 3.8         Notices.
All notices and other communications under this Agreement between the Parties shall be in writing and shall be deemed to have been duly
given, delivered and received (a) when delivered in person, (b) when delivered after posting in the U.S. mail, having been
sent registered or certified mail, return receipt requested, postage prepaid, (c) when delivered by FedEx or another nationally
recognized overnight delivery service or (d) when delivered by email (provided that, if receipt has not been confirmed (excluding
any automated reply, such as an out-of-office notification) then a copy shall be dispatched in the manner described in the preceding
clause (c) no later than 24 hours after such delivery by email) addressed as follows:

 

If to Acquiror prior to the Effective Time, to:

 

AMCI
Acquisition Corp. II

600 Steamboat Road

Greenwich, CT 06830

Attn:         Nimesh Patel

E-mail:     [***]

 

    	 	9	 

     

    

 

and

 

White & Case LLP

1221 Avenue of the Americas

New York, NY 10020-1095

Attn:         Emery Choi, Oliver Wright and Elliot Smith

E-mail:     [***], [***] and [***]

 

If to Acquiror following the Effective Time or to the Company,
to:

 

LanzaTech NZ, Inc.

8045 Lamon Avenue, Suite 400

Skokie, IL 60077

Attention: Mark Burton

Email: [***]

 

with copies (which shall not constitute notice) to:

 

Covington & Burling LLP

Salesforce Tower

415 Mission Street, Suite 5400

San Francisco, CA 94105

Attention: Denny Kwon

Email: [***]

 

and

 

Covington & Burling LLP

3000 El Camino Real

5 Palo Alto Square, 10th Floor

Palo Alto, CA 94306

Attention: Scott A. Anthony

Email: [***]

 

If to an Insider Holder, to the email address set forth below
such Insider Holder’s name in Schedule I

 

with copies (which shall not constitute notice) to:

 

White & Case LLP

1221 Avenue of the Americas

New York, NY 10020-1095

Attn:         Emery Choi, Oliver Wright and Elliott Smith

E-mail:     [***], [***] and [***]

 

    	 	10	 

     

    

 

Section 3.9         Other
Provisions. The provisions set forth in each of Sections 12.6 (Governing Law), 12.13 (Severability), 11.14 (Jurisdiction;
Waiver of Trial By Jury) and 12.15 (Enforcement) of the Merger Agreement are incorporated herein by reference as if set forth
herein, mutatis mutandis.

 

Section 3.10         Entire
Agreement. This Agreement constitutes the entire agreement and understanding of the Parties with respect to the subject matter hereof
and supersede all prior understandings, agreements and representations by or among the Parties hereto to the extent they relate in any
way to the subject matter hereof.

 

Section 3.11         Counterparts.
This Agreement may be executed in any number of counterparts, each of which shall be deemed an original, but all of which together shall
constitute one and the same instrument. Delivery of an executed counterpart of a signature page to this Agreement by facsimile,
e-mail, or scanned pages shall be effective as delivery of a manually executed counterpart to this Agreement.

 

Section 3.12         Capacity
as a Stockholder. Notwithstanding anything herein to the contrary, each Insider Holder signs this Agreement solely in such Insider
Holder’s capacity as a stockholder of Acquiror, and not in any other capacity and this Agreement shall not limit or otherwise affect
the actions of the Insider Holder or any Affiliate, employee or designee of the Insider Holder or any of their respective Affiliates
in his or her capacity, if applicable, as an officer or director of Acquiror or any other Person.

 

[Remainder of page intentionally left
blank.]

 

    	 	11	 

     

    

 

IN WITNESS WHEREOF, each of
the Parties has caused this Agreement to be duly executed as of the date first written above.

 

	 	INSIDER HOLDERS
	 	 
	 	SPONSOR:
	 	 
	 	AMCI SPONSOR II LLC
	 	 
	 	 
	 	By:	/s/ Nimesh Patel
	 	Name: 	Nimesh Patel
	 	Title:  	Chief Executive Officer
	 	 
	 	 
	 	AMCI Group, LLC Series 35
	 	 
	 	 
	 	By:	/s/ Hans Mende
	 	Name: 	Hans Mende
	 	Title:  	Authorized Signatory
	 	 
	 	/s/ Nimesh Patel
	 	Name:	Nimesh Patel
	 	 
	 	/s/ Brian Beem
	 	Name:	Brian Beem
	 	 
	 	/s/ Patrick Murphy
	 	Name:	Patrick Murphy
	 	 
	 	/s/ Walker Woodson
	 	Name:	Walker Woodson
	 	 
	 	/s/ Kate Burson
	 	Name:	Kate Burson
	 	 
	 	/s/ Adrian Paterson
	 	Name:	Adrian Paterson
	 	 
	 	/s/ Mark Pinho
	 	Name:	Mark Pinho
	 	 
	 	/s/ Jill Watz
	 	Name:	Jill Watz
	 	 
	 	/s/ Morgan Holmes
	 	Name:	Morgan Holmes
	 	 
	 	/s/ Henry Copses
	 	Name:	Henry Copses

 

[Signature Page of Sponsor Support Agreement]

 

     

     

    

 

	 	ACQUIROR:
	 	 
	 	AMCI ACQUISITION CORP. II
	 	 
	 	 
	 	By:	/s/ Nimesh Patel
	 	 	Name:	Nimesh Patel
	 	 	Title:	Chief Executive Officer

 

[Signature Page of Sponsor Support Agreement]

 

     

     

    

 

	 	COMPANY:
	 	 
	 	LANZATECH NZ, INC.
	 	 
	 	 
	 	By:	/s/ Jennifer Holmgren
	 	 	Name:	Jennifer Holmgren
	 	 	Title:	Chief Executive Officer

 

[Signature Page to Sponsor Support Agreement]

 

     

     

    

 

Schedule I

 

Acquiror Common Shares and Private Placement
Warrants

 

 

[Omitted.] 

 

[Schedule I of Sponsor
Support Agreement]

 

     

     

    

 

Exhibit A

 

Illustrative Promote Shares Forfeiture Schedule

 

	Redemption Percentage	 	 	100	%	 	 	90	%	 	 	80	%	 	 	70	%	 	 	60	%	 	 	51	%	 	 	50	%
	# of Promote Shares Forfeited (assuming 3,750,000 Promote
    Shares outstanding)	 	 	1,250,000	 	 	 	1,000,000	 	 	 	750,000	 	 	 	500,000	 	 	 	250,000	 	 	 	25,000	 	 	 	0	 

 

[Exhibit A of Sponsor Support Agreement]

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