EXHIBIT 4.4

      

      

      DESCRIPTION OF THE REGISTRANT’S SECURITIES

      REGISTERED PURSUANT TO SECTION 12 OF THE

      SECURITIES EXCHANGE ACT OF 1934

      

      

      As of March 23, 2021, Advent Technologies Holdings, Inc. has two classes of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”): (1) common stock and (2) warrants.

      

      

      The following description of the common stock and warrants is a summary and does not purport to be complete. It is subject to and qualified in its entirety by reference to our
        second amended and restated certificate of incorporation (the “Charter”) and our amended and restated bylaws (the “Bylaws”),
        each of which are incorporated by reference as an exhibit to the Annual Report on Form 10-K of which this Exhibit 4.4 is a part. We encourage you to read our Charter, our Bylaws and the applicable provisions of Delaware General Corporations
        Law (“DGCL”) (Title 8, Chapter 1 of the Delaware Code).

      

      

      Terms not otherwise defined herein shall have the meaning assigned to them in the Annual Report on Form 10-K of which this Exhibit 4.4 is a part.

      

      

      Authorized and Outstanding Capital Stock

      

      

      Pursuant to our Charter, the total number of shares of capital stock that we are authorized to issue is 111,000,000 shares, consisting of two classes as follows: (i) 110,000,000
        shares of common stock, par value $0.0001 per share (the “common stock”), and (ii) 1,000,000 shares of preferred stock, par value $0.0001 per share.

      

      

      As of March 23, 2021, our issued and outstanding share capital consisted of: (i) 46,105,947 shares of common stock, held of record by approximately 74 holders, (ii) no shares of
        preferred stock and (iii) 26,392,355 warrants, consisting of 22,052,077 public warrants issued in our initial public offering, 3,940,278 warrants sold in a private placement that closed simultaneously with our initial public offering and 400,000
        working capital warrants, held of record by approximately 6 warrant holders. Such numbers do not include DTC participants or beneficial owners holding shares through nominee names.

      

      

      Common Stock

      

      

      Voting Rights

      

      

      Except as otherwise required by law or the second amended and restated certificate of incorporation, holders of common stock are entitled to one vote for each share of common stock
        held of record by such holder on all matters on which stockholders are generally entitled to vote; provided, that, except as otherwise required by law, holders of common stock shall not be entitled to vote on any amendment to the second amended and
        restated certificate of incorporation that relates solely to the terms of one or more outstanding series of preferred stock if the holders of such affected series of preferred stock are entitle, either separately or together with the holders of one
        or more other such series of preferred stock, to vote thereon pursuant to the second amended and restated certificate of incorporation or the DGCL.

      

      

      Dividend Rights

      

      

      The board of directors may from time to time declare, and the Company may pay, dividends (payable in cash, property or shares of capital stock) on the Company’s outstanding shares
        of capital stock, subject to applicable law and the second amended and restated certificate of incorporation.

      

      

      Liquidation, Dissolution and Winding Up

      

      

      On the liquidation, dissolution, distribution of assets or winding up of the Company, each holder of shares of common stock will be entitled, pro rata on a per share basis, to all
        assets of the Company of whatever kind available for distribution to the holders of common stock, subject to the designations, preferences, limitations, restrictions and relative rights of any other class or series of preferred stock then
        outstanding.

        

      

      
        
          


      

      Preemptive or Other Rights

      

      

      Our stockholders have no preemptive or other subscription rights and there are no sinking fund or redemption provisions applicable to our common stock.

      

      

      Preferred Stock

      

      

      The second amended and restated certificate of incorporation provides that shares of preferred stock may be issued from time to time in one or more series. Our board of directors
        will be authorized to fix the voting rights, if any, designations, powers, preferences, the relative, participating, optional or other special rights and any qualifications, limitations and restrictions thereof, applicable to the shares of each
        series. Our board of directors will be able to, without stockholder approval, issue preferred stock with voting and other rights that could adversely affect the voting power and other rights of the holders of the common stock and could have
        anti-takeover effects. The ability of our board of directors to issue preferred stock without stockholder approval could have the effect of delaying, deferring or preventing a change of control of us or the removal of existing management. We have
        no preferred stock outstanding at the date hereof. Although we do not currently intend to issue any shares of preferred stock, we cannot assure you that we will not do so in the future. No shares of preferred stock were issued or registered in the
        Business Combination.

      

      

      Warrants

      

      

      Public Warrants

      

      

      There are currently outstanding an aggregate of 22,052,077 public warrants, which entitle the holder to acquire common stock. Each whole warrant will entitle the registered holder
        to purchase one share of common stock at a price of $11.50 per share, subject to adjustment as discussed below, beginning 30 days after closing of the Business Combination (which for the avoidance of doubt is March 6, 2021). The public warrants
        will expire five years after closing of the Business Combination, at 5:00 p.m., New York City time, or earlier upon redemption or liquidation.

      

      

      Redemption of Warrants for Cash

      

      

      Once the public warrants become exercisable, we may call the warrants for redemption for cash:

      

      

      	

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              in whole and not in part;

            


      	

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              at a price of $0.01 per warrant;

            


      	

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              upon not less than 30 days’ prior written notice of redemption (the “30-day redemption period”) to each warrant holder; and

            


      	

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              if, and only if, the closing price of our common stock equals or exceeds $18.00 per share (as adjusted for stock splits, stock capitalizations, reorganizations, recapitalizations and the like) for any 20 trading days within a 30-trading
                day period ending three business days before we send the notice of redemption to the warrant holders.

            


      

      

      If and when the public warrants become redeemable by us, we may not exercise our redemption right if the issuance of shares of common stock upon exercise of the warrants is not
        exempt from registration or qualification under applicable state blue sky laws or we are unable to effect such registration or qualification.

      

      

      We have established the last of the redemption criteria discussed above to prevent a redemption call unless there is at the time of the call a significant premium to the warrant
        exercise price. If the foregoing conditions are satisfied and we issue a notice of redemption of the public warrants, each warrantholder will be entitled to exercise its warrant prior to the scheduled redemption date. However, the price of our
        common stock may fall below the $18.00 redemption trigger price (as adjusted for stock splits, stock dividends, reorganizations, recapitalizations and the like) as well as the $11.50 warrant exercise price after the redemption notice is issued.

       

      

      
        
          


      

      Redemption procedures and cashless exercise

      

      

      If we call the public warrants for redemption as described above, our management will have the option to require any holder that wishes to exercise its warrant to do so on a
        “cashless basis.” In determining whether to require all holders to exercise their warrants on a “cashless basis,” our management will consider, among other factors, our cash position, the number of warrants that are outstanding and the dilutive
        effect on our stockholders of issuing the maximum number of shares of common stock issuable upon the exercise of our warrants. If our management takes advantage of this option, all holders of public warrants would pay the exercise price by
        surrendering their warrants for that number of shares of common stock equal to the quotient obtained by dividing (x) the product of the number of shares of common stock underlying the warrants, multiplied by the difference between the exercise
        price of the warrants and the “fair market value” (defined below) by (y) the fair market value. The “fair market value” shall mean the average reported last sale price of the common stock for the 10 trading days ending on the third trading day
        prior to the date on which the notice of redemption is sent to the holders of warrants. If our management takes advantage of this option, the notice of redemption will contain the information necessary to calculate the number of shares of common
        stock to be received upon exercise of the public warrants, including the “fair market value” in such case. Requiring a cashless exercise in this manner will reduce the number of shares to be issued and thereby lessen the dilutive effect of a
        warrant redemption. We believe this feature is an attractive option to us if we do not need the cash from the exercise of the warrants after the Closing. If we call our public warrants for redemption and our management does not take advantage of
        this option, Sponsor and its permitted transferees would still be entitled to exercise their placement warrants and working capital warrants for cash or on a cashless basis using the same formula described above that other warrantholders would have
        been required to use had all warrantholders been required to exercise their warrants on a cashless basis, as described in more detail below.

      

      

      A holder of a public warrant may notify us in writing in the event it elects to be subject to a requirement that such holder will not have the right to exercise such warrant, to
        the extent that after giving effect to such exercise, such person (together with such person’s affiliates), to the warrant agent’s actual knowledge, would beneficially own in excess of 4.9% or 9.8% (or such other amount as a holder may specify) of
        the shares of common stock outstanding immediately after giving effect to such exercise.

      

      

      Anti-Dilution Adjustments

      

      

      If the number of outstanding shares of common stock is increased by a stock dividend payable in shares of common stock, or by a split-up of shares of common stock or other similar
        event, then, on the effective date of such stock dividend, split-up or similar event, the number of shares of common stock issuable on exercise of each public warrant will be increased in proportion to such increase in the outstanding shares of
        common stock. A rights offering to holders of common stock entitling holders to purchase shares of common stock at a price less than the fair market value will be deemed a stock dividend of a number of shares of common stock equal to the product
        of  (i) the number of shares of common stock actually sold in such rights offering (or issuable under any other equity securities sold in such rights offering that are convertible into or exercisable for common stock) and (ii) one (1) minus the
        quotient of (x) the price per share of common stock paid in such rights offering divided by (y) the fair market value. For these purposes (i) if the rights offering is for securities convertible into or exercisable for common stock, in determining
        the price payable for common stock, there will be taken into account any consideration received for such rights, as well as any additional amount payable upon exercise or conversion and (ii) fair market value means the volume weighted average price
        of common stock as reported during the ten (10) trading day period ending on the trading day prior to the first date on which the shares of common stock trade on the applicable exchange or in the applicable market, regular way, without the right to
        receive such rights.

      

      

      In addition, if we, at any time while the public warrants are outstanding and unexpired, pay a dividend or make a distribution in cash, securities or other assets to the holders of
        common stock on account of such shares of common stock (or other shares of our capital stock into which the warrants are convertible), other than (a) as described above or (b) certain ordinary cash dividends, then the warrant exercise price will be
        decreased, effective immediately after the effective date of such event, by the amount of cash and/or the fair market value of any securities or other assets paid on each share of common stock in respect of such event.

       

      

      
        
          


      

      If the number of outstanding shares of our common stock is decreased by a consolidation, combination, reverse stock split or reclassification of shares of common stock or other
        similar event, then, on the effective date of such consolidation, combination, reverse stock split, reclassification or similar event, the number of shares of common stock issuable on exercise of each public warrant will be decreased in proportion
        to such decrease in outstanding shares of common stock.

      

      

      Whenever the number of shares of common stock purchasable upon the exercise of the public warrants is adjusted, as described above, the warrant exercise price will be adjusted by
        multiplying the warrant exercise price immediately prior to such adjustment by a fraction (x) the numerator of which will be the number of shares of common stock purchasable upon the exercise of the warrants immediately prior to such adjustment,
        and (y) the denominator of which will be the number of shares of common stock so purchasable immediately thereafter.

      

      

      In case of any reclassification or reorganization of the outstanding shares of common stock (other than those described above or that solely affects the par value of such shares of
        common stock), or in the case of any merger or consolidation of us with or into another corporation (other than a consolidation or merger in which we are the continuing corporation and that does not result in any reclassification or reorganization
        of our outstanding shares of common stock), or in the case of any sale or conveyance to another corporation or entity of the assets or other property of us as an entirety or substantially as an entirety in connection with which we are dissolved,
        the holders of the public warrants will thereafter have the right to purchase and receive, upon the basis and upon the terms and conditions specified in the warrants and in lieu of the shares of our common stock immediately theretofore purchasable
        and receivable upon the exercise of the rights represented thereby, the kind and amount of shares of stock or other securities or property (including cash) receivable upon such reclassification, reorganization, merger or consolidation, or upon a
        dissolution following any such sale or transfer, that the holder of the warrants would have received if such holder had exercised their warrants immediately prior to such event. If less than 70% of the consideration receivable by the holders of
        common stock in such a transaction is payable in the form of common stock in the successor entity that is listed for trading on a national securities exchange or is quoted in an established over-the-counter market, or is to be so listed for trading
        or quoted immediately following such event, and if the registered holder of the warrant properly exercises the warrant within thirty days following public disclosure of such transaction, the warrant exercise price will be reduced as specified in
        the warrant agreement based on the Black-Scholes value (as defined in the warrant agreement) of the warrant. The purpose of such exercise price reduction is to provide additional value to holders of the warrants when an extraordinary transaction
        occurs during the exercise period of the warrants pursuant to which the holders of the warrants otherwise do not receive the full potential value of the warrants in order to determine and realize the option value component of the warrant. This
        formula is to compensate the warrant holder for the loss of the option value portion of the warrant due to the requirement that the warrant holder exercise the warrant within 30 days of the event. The Black-Scholes model is an accepted pricing
        model for estimating fair market value where no quoted market price for an instrument is available.

      

      

      The public warrants and the placement warrants were issued in registered form under a warrant agreement between Continental Stock Transfer & Trust Company, as warrant agent,
        and AMCI. You should review a copy of the warrant agreement, which has been publicly filed with the SEC and which you can find in the list of exhibits to this registration statement, for a complete description of the terms and conditions applicable
        to the warrants. The warrant agreement provides that the terms of the warrants may be amended without the consent of any holder to cure any ambiguity or correct any defective provision, but requires the approval by the holders of at least 65% of
        the then outstanding public warrants to make any change that adversely affects the interests of the registered holders of public warrants.

      

      

      The public warrants may be exercised upon surrender of the warrant certificate on or prior to the expiration date at the offices of the warrant agent, with the exercise form on the
        reverse side of the warrant certificate completed and executed as indicated, accompanied by full payment of the exercise price (or on a cashless basis, if applicable), by certified or official bank check payable to us, for the number of warrants
        being exercised. The warrantholders do not have the rights or privileges of holders of common stock and any voting rights until they exercise their warrants and receive shares of common stock. After the issuance of shares of common stock upon
        exercise of the warrants, each holder will be entitled to one (1) vote for each share held of record on all matters to be voted on by stockholders.

      

      

      No fractional shares will be issued upon exercise of the public warrants. If, upon exercise of the warrants, a holder would be entitled to receive a fractional interest in a share,
        we will, upon exercise, round down to the nearest whole number of shares of common stock to be issued to the warrantholder.

       

      

      
        
          


      

      Placement Warrants

      

      

      The Sponsor purchased an aggregate of 5,500,000 Placement Warrants at a purchase price of $1.00 per Placement Warrant for an aggregate purchase price of $5,500,000 in a private
        placement that occurred on the closing date of our initial public offering.

      

      

      Except as described below, the placement warrants have terms and provisions that are identical to those of the public warrants, including as to exercise price, exercisability and
        exercise period. The placement warrants (including the common stock issuable upon exercise of the placement warrants) are not transferable, assignable or salable until 30 days after the Closing (except, among certain other limited exceptions to our
        officers and directors and other persons or entities affiliated with Sponsor) and they will not be redeemable by us so long as they are held by Sponsor or its permitted transferees. Sponsor, or its permitted transferees, has the option to exercise
        the placement warrants on a cashless basis. If the placement warrants are held by holders other than Sponsor or its permitted transferees, the placement warrants will be subject to the same terms and conditions as the public warrants, and among
        other matters, be redeemable by us and exercisable by the holders on the same basis as the public warrants.

      

      

      If holders of the placement warrants elect to exercise them on a cashless basis, they would pay the exercise price by surrendering their warrants for that number of shares of
        common stock equal to the quotient obtained by dividing (x) the product of the number of shares of common stock underlying the warrants, multiplied by the difference between the exercise price of the warrants and the “fair market value” (defined
        below) by (y) the fair market value. The “fair market value” shall mean the average reported last sale price of the common stock for the 10 trading days ending on the third trading day prior to the date on which the notice of warrant exercise is
        sent to the warrant agent.

      

      

      Working Capital Warrants

      

      

      In order to finance transaction costs in connection with an intended initial business combination, Sponsor made a non-interest bearing loan to the Company of $400,000, which was
        due at the earlier of the date on which AMCI consummates the Business Combination or February 22, 2021. In connection with the Closing, such loan was converted into warrants (referred to in this prospectus as working capital warrants) at a price of
        $1.00 per warrant at the option of the lender. Such working capital warrants are identical to the placement warrants, including as to exercise price, exercisability and exercise period. The terms of such working capital loans by Sponsor or its
        affiliates, or our officers and directors, if any, have not been determined and no written agreements exist with respect to such loans.

      

      

      Dividends

      

      

      We have not paid any cash dividends on our common stock to date. The payment of cash dividends in the future will be dependent upon our revenues and earnings, if any, capital
        requirements and general financial conditions. The payment of any cash dividends is within the discretion of our board of directors at such time. Further, if we incur any indebtedness, our ability to declare dividends may be limited by restrictive
        covenants we may agree to in connection therewith.

      

      

      Transfer Agent and Warrant Agent

      

      

      The transfer agent for our common stock and warrant agent for our warrants is Continental Stock Transfer & Trust Company. We have agreed to indemnify Continental Stock Transfer
        & Trust Company in its roles as transfer agent and warrant agent, its agents and each of its stockholders, directors, officers and employees against all claims and losses that may arise out of acts performed or omitted for its activities in
        that capacity, except for any liability due to any gross negligence, willful misconduct or bad faith of the indemnified person or entity.

      

      

      Certain Anti-Takeover Provisions of Delaware Law and our Second Amended and Restated Certificate of Incorporation and Amended and Restated Bylaws

       

      

      
        
          


      

      We are subject to the provisions of Section 203 of the DGCL regulating corporate takeovers. This statute prevents certain Delaware corporations, under certain circumstances, from
        engaging in a “business combination” with:

      

      

      	

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              a stockholder who owns 15% or more of our outstanding voting stock (otherwise known as an “interested stockholder”);

            


      	

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              an affiliate of an interested stockholder; or

            


      	

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              an associate of an interested stockholder, for three years following the date that the stockholder became an interested stockholder.

            


      

      

      A “business combination” includes a merger or sale of more than 10% of our assets. However, the above provisions of Section 203 do not apply if:

      

      

      	

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              our board of directors approves the transaction that made the stockholder an “interested stockholder,” prior to the date of the transaction; or

            


      	

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              after the completion of the transaction that resulted in the stockholder becoming an interested stockholder, that stockholder owned at least 85% of our voting stock outstanding at the time the transaction commenced, other than
                statutorily excluded shares of common stock.

            


      

      

      Forum Selection Clause

      Rule 144

      Registration Rights

      Listing of Securities

      

      

      Our common stock and warrants are listed on Nasdaq under the symbols “ADN” and “ADNWW”, respectively.