<PAGE>

                                 EXHIBIT 10.20

                            Engelhard Corporation
                                  Development
                                   Agreement










<PAGE>

                             DEVELOPMENT AGREEMENT

     This Agreement memorializes a relationship made and entered into this
nineteenth day of January, 1999, by and between and Hydrogen Burner
Technology, Inc., having a place of business at 3925 Vernon Street, Long
Beach, California 90815 ("HBT"), and Engelhard Corporation, having a place of
business at 101 Wood Avenue, Iselin, New Jersey 08830-0770 ("ENGELHARD").


1.   RECITALS
     1.1  Engelhard has developed and continues to develop technology related
to catalyst products and manufactures catalyst products, including catalyst
compositions, catalyzed articles and catalyst systems, including catalysts
useful in the various components of a fuel cell including fuel processors and
fuel cell stacks. Engelhard has also developed and continues to develop
technology related to fuel processors and related equipment for use in fuel
cell systems. The principal role of Engelhard under this Agreement is to
provide existing or develop and provide catalysts, and related methods of
application, for use with a stationary fuel processor, and/or components
thereof as determined by the parties.

     1.2  HBT has developed and continues to develop technology related to
fuel processors, fuel processor systems and related equipment for use in fuel
cell systems as well as industrial hydrogen generators. HBT, separately and
combined with its subcontractor have developed and continue to develop
technology related to catalyst products useful for stationary and mobile fuel
cell systems utilizing gaseous and liquid hydrocarbon fuels. Specific
technology of HBT relates to precious metal, iron/chromium and copper/zinc
based shift catalysts. However, HBT is not a commercial catalyst
manufacturer. HBT has filed a patent application relating to shift catalysts
useful in fuel processors. The principal role of HBT under this Agreement is
to provide existing or develop and provide a stationary fuel processor,
and/or components thereof for use with catalysts and related methods as
determined by the parties.

     1.3  HBT and Engelhard desire to work together to combine Engelhard's
proprietary catalyst technology with HBT's proprietary fuel processor related
technology to develop a fuel processor that will be


<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 2

used for residential and small stationary commercial fuel cell systems. In
particular initial projects are envisioned to relate to the development of
Stationary Autothermal Fuel Processors, as defined below. The fuel processors
to be developed hereunder shall use any suitable fuel including but not
limited to natural gas, methane, or propane.

     In consideration of the foregoing and the terms set forth below, the
parties agree as follows:

2.   DEFINITIONS
     The following terms shall have, for the purposes of this Agreement, the
meanings set forth in this Article 2. Although defined in the singular, the
terms may be used in this Agreement in the plural as well as the singular
form.

     2.1  "Catalyst" shall mean catalyst, catalytic adsorbers, catalytic
absorbers and/or reactive compositions which are useful to catalyze the
oxidation and/or reduction of, or otherwise treat, carbon monoxide, hydrogen,
hydrocarbons including natural gas and includes catalyst compositions
supported on carriers such as honeycomb monoliths, plates, pipes, hardware
and other catalyzed components related to a fully integrated fuel processor,
with specific catalysts including CO preferential oxidation catalysts and
autothermal reforming catalysts, oxidation catalysts for the abatement of
hydrogen from the anode, and shift catalysts which are catalysts that
catalyze a gas stream comprising hydrogen, carbon monoxide and water to
increase the hydrogen concentration and decrease the carbon monoxide
concentration of the gas stream.

     2.2  "Sorbent" shall mean non-catalytic adsorbent and/or absorbent which
can adsorb and/or absorb materials such as sulfur containing molecules.

     2.3  "Fuel Processor" shall mean a system for converting hydrocarbon
fuels (e.g., natural gas, methane, propane, etc.) to a gas containing
hydrogen that is suitable for acceptable operation at the fuel cell anode.
The system may consist of hardware and control components designed to employ
catalysts in reactor, exchanger, shift, CO polishing or treatment subsystems.






<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 3

     2.4  "Fuel Cell" shall mean an electrochemical cell used to convert fuel
(e.g. Hydrogen (H2)) from the Fuel Processor to electrical energy, and may
contain a plurality of unit cells which in turn may contain a plurality of
catalytic anodes, cathodes and porous plates.

     2.5  "Program" shall mean the joint effort of the parties pursuant to
this Agreement to design and develop one or more Fuel Processors and/or
components thereof that will be used for residential and small stationary
commercial Fuel Cell systems. The Fuel Processor(s) will be designed to be
used to convert gaseous fuel, such as natural gas, methane or propane to
hydrogen with low concentrations of carbon monoxide which are acceptable for
use in Fuel Cell stacks.

     2.6  "Stationary Autothermal Fuel Processor" also referred to as "SAFP"
shall mean a Fuel Processor which is a combination of a catalytic partial
oxidation unit, a steam reforming unit, water gas shift units, a preferential
oxidation unit and optionally a sulfur removal unit. Autothermal reforming
refers to the combination of catalytic partial oxidation and steam
reforming. Preferential oxidation refers to the reduction of carbon monoxide
to concentrations acceptable for use in Fuel Cell stacks.

     2.7  "Projects" shall mean projects relating to the Program which are
agreed to by the parties from time to time and are within the scope of
Exhibit A, made a part hereof, and as may be modified in writing, by mutual
agreement, with an initial Project envisioned to be the joint development of
one or more Stationary Autothermal Fuel Processors.

     2.8  "Project Patent Property" shall mean any patent applications or
patents relating to and/or having claims covering technology relating to the
Fuel Processor, Catalyst, Sorbent or elements thereof developed by the
parties hereunder and based on work done pursuant to Projects agreed upon
hereunder.

     2.9  "Technical Information" shall mean information and samples relating
to the Program which either party has in its possession or hereafter develops
and is lawfully free to disclose to the other hereunder without obligation to
third parties, and considers necessary in furtherance of the Program.

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 4

     2.10 "Background Patent Rights" shall mean inventions relevant to and
useful in the work done pursuant to Projects agreed upon hereunder, which
inventions were conceived prior to the above written Effective Date of this
Agreement whether patented or an application for patent under the Patent
Laws of the United States of America or any foreign country. Background
Patent Rights shall include the patent application and any related patents or
patent applications or HBT referenced in Section 1.2 hereof and relating to
shift catalysts useful in Fuel Processors.

     2.11 "Affiliated Company" shall mean any company or entity owned by, or
having common ownership with either party to this Agreement, or being a joint
venture partner of either party to this Agreement. Ownership of a company or
entity as used herein means the direct or indirect ownership of more than
fifty percent (50%) of the voting shares or share capital, equity or voting
rights of the company or entity except that Affiliate shall include
Engelhard's affiliates N.E. ChemCat Co., Ltd. of Japan and Heesung Engelhard
of South Korea, and HBT's Phoenix Gas Systems.

     2.12 "Net Sales" of Fuel Processors and/or components thereof including
Catalysts used specifically for such Fuel Processors or components thereof,
shall mean the amount actually billed for the sales of said systems, parts
and/or components thereof after deducting from gross sales price: (i) normal
and customary cash and trade discounts, credit for returns and allowances,
(ii) insurance costs and transportation charges and allowances, (iii) sales
or other excise taxes or duties imposed upon and paid by the party selling
said products with respect to such sales and (iv) selling commissions by
resellers or trading agents, if any, paid by the party selling said products.

     2.13 "Effective Date" shall mean January 19, 1999.

3.   PROGRAM FOR ESTABLISHMENT AND DETERMINATION
     OF PROJECTS AND EXCHANGE OF TECHNICAL INFORMATION

     3.1  Pursuant to the Program, HBT and Engelhard will cooperate in the
development of one or more Fuel Processors and related Catalysts in
accordance with the Project recited in Exhibit A. It is understood the
parties may exchange Technical Information reasonably required by the

<PAGE>


HYDROGEN BURNER TECHNOLOGY, INC.
Page 5

other to perform and evaluate their respective contributions to the Program.
However, except as recited in this Agreement, neither of the parties is
obligated to provide Technical Information to the other party.  HBT and
Engelhard shall pursue the Progam as it may be amended in writing by the
parties from time to time unless they determine jointly or separately, in
good faith, that the Program will not result in a commercially feasible Fuel
Processor, at which time the Agreement can be terminated consistent with
Article 13 below.

      3.2  Within ninety (90) days after the Effective Date, authorized
representatives of Engelhard and HBT shall meet for the purpose of outlining
the initial Project or Projects, within the scope of the Program, to be
undertaken.  Such authorized representatives shall agree on the Projects in
writing and shall include the nature, scope, estimated resource requirements,
the estimated completion date, and the procedures to be followed for
implementing same.  A written summary of each such Project, upon mutual
agreement of the parties, shall be incorporated into Exhibit A and made a
part of this Agreement.

      3.3  Each party shall bear its own costs and expenses with respect to
the Program, except as may otherwise be agreed.  Unless otherwise agreed,
each party will determine the testing which it shall conduct and pay for its
own testing.  HBT and Engelhard shall mutually agree upon testing to be
conducted by third parties and which party shall bear the costs.  The results
of testing by a party, HBT or Engelhard, shall be disclosed to the other
party, and shall be the Technical Information of the disclosing party.  All
test results obtained by third parties shall be provided to both HBT and
Engelhard and shall be the jointly owned Technical Information of both HBT
and Engelhard.

      3.4  A database shall be kept jointly by HBT and Engelhard to indentify
           the degree of participation each party provides for new proprietary
           intellectual property including whether the inventions were solely
           or jointly developed. A listing of such intellectual property is
           provided on Exhibit C, made a part hereof, and as may be modified
           in writing, by mutual agreement of the parties.


<PAGE>


HYDROGEN BURNER TECHNOLOGY, INC.
Page 6

      3.5  No party shall encumber or obligate another party in any manner,
including agreeing to a project for a customer, without the written agreement
of the other party.

4.  INTELLECTUAL PROPERTY

    4.1  All Technical Information developed soley by Engelhard and Project
Patent Properties based on inventions made solely by Engelhard employees
shall be the sole property of Engelhard.

    4.2  All Technical Information developed solely by HBT and Project Patent
Properties based on inventions made solely by HBT employees shall be the sole
property of HBT.

    4.3  Each party shall have the sole right to determine whether and in
which countries it shall make applications for Project Patent Properties on
inventions which are their respective sole property as recited in Sections 4.1
and 4.2.

    4.4  All Technical Information jointly developed hereunder and based on
work pursuant to Project(s), and Project Patent Properties based on
inventions made jointly by Engelhard and HBT employees shall be jointly
owned.  The parties shall, upon mutual agreement, determine whether patent
applications shall be filed for joint inventions, and which party shall file
such applications, including foreign applications and all costs therefor,
including costs of issue and maintenance.  Any resulting patent shall be
jointly owned.  In countries where one party desires to file a Project Patent
Property based on such joint invention and the other party does not, the
party causing the filing to be made shall be the sole owner thereof.  Subject
to Article 5, the other party shall have unlimited right and license under
said Project Patent Property with right to sublicense.

    4.5  No party shall abandon any Project Patent Property under its control
without notifying the other party of such fact in reasonable time for the
other party to assume prosecution or maintenance of such patent if it so
desires.  If such other party assumes prosecution or maintenance of such
patent, each party shall thereafter have the same rights relative to such
patent as if the party which assumes prosecution or maintenance had caused
such patent to be filed initially.  A party which is the


<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 7

proprietor of a Project Patent Property shall not be liable to the other
party for inadvertent abandonment of said Project Patent Property.

     4.6  Except as otherwise provided, and in order to carry out the
foregoing, each party shall, at the request and expense of the other party,
use reasonable efforts to execute or cause to be executed such assignments or
other papers relating to Project Patent Properties as the requesting party
may require.

5.   LICENSES AND ROYALTIES
     5.1  With regard to Catalysts, Sorbents and Fuel Processors which are
the subject of jointly owned Project Patent Properties and jointly developed
Technical Information, for a period of three (3) years from December 31,
2001: (i) Engelhard shall have a royalty-free exclusive right and license,
with right to sublicense, to manufacture, have manufactured, use and sell
Catalysts and Sorbents; and (ii) HBT shall have a royalty-free exclusive
right and license, with right to sublicense to manufacture, have
manufactured, use and sell Fuel Processors and components thereof.

     5.2  Upon expiration of the three (3) period recited in Section 5.1,
each party shall have a royalty-free nonexclusive right and license, to
manufacture, have manufactured, use and sell Catalysts, Sorbents and Fuel
Processors and components thereof, which are the subject of jointly owned
Project Patent Properties and jointly developed Technical Information.

     5.3  Upon expiration of the three (3) period recited in Section 5.1, (i)
Engelhard shall have a royalty-free right to license jointly owned Project
Patent Properties and jointly developed Technical Information relating to
Catalysts and Sorbents to any party, and jointly owned Project Patent
Properties and jointly developed Technical Information relating to Fuel
Processors to any Affiliate; and the right to license jointly owned Project
Patent Properties and jointly developed Technical Information relating Fuel
Processors to any unrelated party at a reasonable royalty to HBT; and (ii)
HBT shall have a royalty-free right to license jointly owned Project Patent
Properties and jointly developed Technical Information relating to Fuel
Processors to any party, and

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 8

jointly owned Project Patent Properties and jointly developed Technical
Information relating to Catalysts and Sorbents to any Affiliate; and the
right to license jointly owned Project Patent Properties and jointly
developed Technical Information relating to Catalysts and Sorbents to any
unrelated party at a reasonable royalty to Engelhard.

     5.4  HBT shall grant to Engelhard, upon request by Engelhard, a
worldwide, sole right and license, with right to sublicense, to manufacture,
have manufactured, use and sell Catalysts which are the subject of HBT
Background Patent Rights in return for a royalty rate based on the Net Sales
to be agreed by the parties.

6.   CONFIDENTIAL INFORMATION
     In order for the parties to proceed with this Agreement, the parties may
exchange information and samples which the disclosing party regards as
confidential. In order to protect the rights of both parties in their
respective confidential information ("INFORMATION") and proprietary samples
("SAMPLES"), the parties hereby agree that such INFORMATION and SAMPLES shall
be exchanged subject to the terms of their Confidentiality Agreement
effective January 1, 1999, between HBT and ENGELHARD. (Exhibit B)

7.   COMMERCIAL ARRANGEMENTS
     7.1  Within thirty (30) days from the date of completion of the
Project(s) described in Exhibit A (but in any case not later than June,
2000), and if the parties have determined to proceed, authorized
representatives of the parties will meet to discuss a business or commercial
plan for the Fuel Processors or components thereof to be developed hereunder
which shall include the possible commercial arrangements between the parties,
such as joint ventures, supply agreements or other arrangements.

     7.2  The parties contemplate initial commercialization of a SAFP with
Plug Power L.L.C. The parties expect to provide one SAFP unit to Plug Power
which is developed under this Agreement. Each of HBT's and Engelhard's
cumulative liability to Plug Power shall be no greater than one half of the
price of the initial SAFP unit to Plug Power. This is

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 9

expected to be a total of $150,000.00 for both HBT and Engelhard or
$75,000.00 maximum liability for each of HBT and Engelhard.

8.   PUBLICITY
     No public release or advertisements by either HBT or Engelhard relating
to the subject of this Agreement shall be made without the agreement of both
parties except to the extent that either party is advised by its counsel that
disclosure of such subject is required by law.

9.   WARRANTIES AND LIMITATION OF LIABILITIES
     9.1  Except for liability associated with Section 7.2, no party shall
be liable to another party in the event that the Project(s) recited in
Section 3.2 cannot be successfully completed.

     9.2  The sole obligation of each party with respect to its Technical
Information, including the results of the Projects of Section 3.2, shall be
to forward same to the other party as provided in this Agreement, and to
correct errors that might have occurred in said Technical Information without
undue delay after such errors are made known to the party which forwarded said
Technical Information.

     THE WARRANTIES SET FORTH IN THIS SECTION 9.2 APPLY TO ALL OF SAID
TECHNICAL INFORMATION LICENSED OR KNOWINGLY DISCLOSED HEREUNDER AND ARE IN
LIEU OF ALL WARRANTIES EXPRESS OR IMPLIED INCLUDING WITHOUT LIMITATION THE
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND THE
WARRANTIES THAT SAID TECHNICAL INFORMATION CAN BE USED WITHOUT INFRINGING
PATENTS AND OTHER RIGHTS OF THIRD PARTIES.

     9.3  Nothing in this Agreement shall obligate either party to apply for,
take out, maintain or acquire any PATENT protection, in any country.

10.  NOTICES
     All notices required to be given hereunder shall be in writing and shall
be given by courier, fax which is confirmed by mail, or first class mail,
postage prepaid, addressed to the parties as follows:

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 10

     To HBT:        Hydrogen Burner Technology, Inc.
                    3925 Vernon Street
                    Long Beach, California 90815
                    Phone: (562) 597-2442; Facsimile: (562) 597-8780
                    Attn: Mr. David Moard, President

     To Engelhard:  Engelhard Corporation
                    101 Wood Avenue South
                    Iselin, NJ 08830-0770
                    Phone: (732) 205-7385; Facsimile: (732) 205-5915
                    Attn: Mr. Daniel W. Parker
                          Group Vice President
                          Separation Systems and Ventures

                    cc:   Vice President & General Counsel

     Either party shall have the right to change the address to which notices
are to be sent by the giving of not less than ten (10) days' written notice
to the other party.

11.  RELATIONSHIP
     The relationship of the parties hereto shall be that of independent
contractors and nothing herein contained shall be deemed to create any
relationship of agency or any partnership.

12.  ENTIRE AGREEMENT
     This Agreement constitutes the entire agreement between the parties
regarding the development of the one or more Fuel Processors and/or
components thereof specified in Exhibit A hereto and supersedes any and all
other prior agreements and understandings whether written, verbal or implied
except for the agreement of Exhibit B made a part hereof. No changes,
alterations or modifications to this Agreement shall be effective unless in
writing and signed by the parties hereto.

13.  TERMINATION
     13.1 This Agreement shall terminate upon successful completion of the
Program but in any event by December 31, 2001, unless further extended by
written agreement of the parties or unless earlier terminated

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 11

as provided below. Either party may terminate this Agreement by ninety (90)
days' written notice to the other party. Upon termination pursuant to this
Article 13, the parties shall be relieved of all obligations under this
Agreement, except for their obligations under this Article 13, Article 6 with
respect to confidential information and their obligations under Articles 4
and 5 as to inventions conceived or reduced to practice prior to such
termination, and warranties and limitation of liabilities recited in
Article 9. Such termination as provided in this Article 13 shall be the only
recourse either party shall have against the other for any discontinuance of
the expenditure of funds on the Program by the other.

     13.2 In the event of termination by a party prior to December 31, 2001,
each party shall have the rights to the jointly developed Technical
Information and Project Patent Properties, and the terminating party, shall
make available all solely developed Technical Information and Project Patent
Properties, developed hereunder, royalty free for the first 100 SAFP units.
Notwithstanding the above, upon termination by Engelhard prior to
December 31, 2001, Engelhard shall have the option to either i) manufacture
Catalysts and Sorbents for use by HBT to manufacture and sell the first 100
SAFP at reasonable terms and conditions; or ii) grant a license HBT to make
or have made Catalysts or Sorbents which are the subject of Engelhard solely
developed Technical Information and Project Patent Properties, developed
hereunder, for use by HBT only to manufacture and sell the first 100.
Additionally, the terminating party shall enter into good faith negotiations
relating to a royalty bearing license for such Technical Information and
Project Patent Properties, developed hereunder, for additional SAFP developed
hereunder; except that neither party shall be obligated to license any solely
owned Catalyst, Sorbent or Fuel Processor related Technical Information and
Project Patent Properties for additional SAFP or other units developed
hereunder.

14.  OTHER DEVELOPMENT
     Either party hereto, subject to its obligations under Article 6 above in
connection with the other party's confidential information, may

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 12

pursue development activity, whether or not similar to the Program, with
others, or independently, provided such activity does not otherwise violate a
party's obligations hereunder. If it is similar, notice shall be provided to
the other party. Engelhard hereby gives notice to HBT that it has a variety
of relationships with other Fuel Processor manufacturers and development
companies including joint development programs relating to Fuel Processors
for mobile applications. HBT hereby gives notice to Engelhard that it has a
variety of relationships with other Catalyst and Fuel Cell development
companies including joint development programs relating to Fuel Processors
for both mobile and stationary applications.

15.  ASSIGNABILITY
     This Agreement may not be assigned by any party without the mutual
written consent of the other parties hereto, which consent shall not be
unreasonably withheld. Except as so provided, any purported assignment shall
be null and void.

16.  JURISDICTION/LAW
     All disputes arising out of or in connection with this Agreement which
cannot be settled among the parties within ninety (90) days of the first
notification by a party of such dispute, shall be finally referred to the
exclusive jurisdiction of the competent court of the party to which the other
party is complaining. This Agreement shall be governed by and construed in
accordance with the laws of New Jersey in the English language.

17.  SEVERABILITY
     In the event that any portion of this Agreement not vital to the main
purpose of this agreement shall be held illegal, void or ineffective, the
remaining portions shall remain in full force and effect.

<PAGE>

HYDROGEN BURNER TECHNOLOGY, INC.
Page 13

18.  HEADINGS
     The headings of Sections of this Agreement are for convenience only, and
shall not in any way affect the interpretation of the Agreement.

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
executed as of the day and year first above written.

<TABLE>
<CAPTION>
<S>                                                     <C>
ENGELHARD CORPORATION                                   HYDROGEN BURNER TECHNOLOGY, INC.

By /s/ Daniel W. Parker              [STAMP]            By /s/ David Moard
   -------------------------------   APPROVED AS TO        -------------------------------
   Daniel W. Parker                  LEGAL FORM         Name   David Moard
   Group Vice President              [ILLEGIBLE]        Title  President
   Separation Systems and
   Ventures

Date   10-14-99                                         Date   10/14/99
     -----------------------------                           -----------------------------
</TABLE>

<PAGE>

EXHIBIT A: JOINT DEVELOPMENT AGREEMENT: ENGELHARD AND HBT

OBJECTIVE: To jointly develop two natural gas-fueled, fuel processors
delivering up to 130 liters of H2/minute with a CO content less than 10 ppm.
Engelhard will be chiefly responsible for the catalysts and HBT the overall
reactor design and its system for control. The jointly developed fuel
processors will be delivered to Plug Power before November 1999.

SCOPE OF WORK:

1.   HBT will provide a general reactor design to Engelhard to accommodate all
     of the catalysts for meeting the subject objectives. HBT will provide
     heat and material balances and Engelhard will advise regarding the final
     design.

2.   Engelhard will provide an autothermal reformer (ATR, (including
     catalyzed partial oxidation (CPO) and steam methane reforming (SMR)
     catalyst sections) and its operating conditions to HBT in accordance to
     their specifications. The system will generate an equivalent of greater
     than 40% (dry volume) H2. HBT will secure the monolithic reactors into
     their reactor hardware. HBT will design the heat management system to
     provide sufficient preheat temperatures to initiate and sustain the ATR
     reaction.

3.   HBT will provide Engelhard with the reactor size requirements for water
     gas shift catalysts (both high temperature shift (HTS) and low
     temperature shift (LTS). Engelhard will supply monoliths and/or tableted
     catalysts along with approximate operating conditions. HBT will provide
     engineering design to meet the desired operating conditions.

4.   Engelhard will supply PROX (preferential oxidation catalyst) and its
     operating conditions (inlet temperature, space velocities and oxygen to
     carbon monoxide ratios) to HBT. HBT will design and build the final
     reactor.

5.   HBT will provide anode vent gas combustors, which Engelhard will coat
     with an active catalyst. The anode gas combustors will be integrated by
     HBT into the heat management system.

<PAGE>

6.   HBT will be responsible for the overall integration, construction and
     testing of the final fuel processor, which will to meet the objective.
     Engelhard will be responsible to provide temperature and poison
     sensitivity of all catalysts.

7.   Engelhard will characterize all catalysts for modes of deactivation.

8.   HBT & Engelhard will share and review test data developed by HBT in
     their test cells on components and systems and by Engelhard in their
     laboratories on representative catalysts. Both parties will work
     together to optimize the performance of the system while minimizing
     costs of the future unit designs.

9.   HBT and Engelhard will support the system testing and operation of units
     at Plug Power with technicians and materials utilizing the shortest
     turnaround times practical.

<PAGE>

                                   EXHIBIT B

                                   AGREEMENT
                                   ---------

     This Agreement is effective as of the first day of January, 1999 by and
between Engelhard Corporation, having a place of business at 101 Wood Avenue,
Iselin, New Jersey 08830-0770 ("ENGELHARD"), and Hydrogen Burner Technology,
Inc., having a place of business at 3925 Vernon Street, Long Beach,
California 90815 ("HBT").

     ENGELHARD has developed and continues to develop certain proprietary
technical and business information, services, processes, materials and
products pertaining to catalyst compositions, catalytic articles and related
products and systems, including catalyst compositions, catalytic articles and
related products and systems useful in the various components of fuel cells
including fuel processors and fuel cell stacks.

     HBT has developed and continues to develop certain proprietary technical
and business information, services, processes, materials including catalysts,
and products pertaining to fuel processors, fuel processor systems for
producing hydrogen containing product gas for commercial hydrogen use and
fuel cells.

     As used herein, the term "INFORMATION" and "SAMPLES" shall refer to the
above-described proprietary information and samples of the respective
parties. ENGELHARD and HBT are willing to exchange INFORMATION and/or SAMPLES
for the sole purpose of determining whether they are willing and able to work
together to develop natural gas fueled fuel processors for fuel cells for
non-automotive applications, and if so, to proceed with such development.

     Therefore, the parties agree as follows:

     1.   Each party will, for a period of five (5) years from the date of
disclosure, maintain all INFORMATION and SAMPLES received, directly or
indirectly, from the other party, secret and confidential, and refrain from
divulging such INFORMATION and SAMPLES to third parties, and use said
INFORMATION and SAMPLES only for the purposes of this Agreement.

     2.   Oral proprietary information shall be identified as INFORMATION at
the time of disclosure and confirmed in writing as INFORMATION within thirty
(30) days after disclosure.

     3.   This obligation of confidentiality and limited use shall not apply
to any INFORMATION received by a party which;

     a.   was in the public domain at the date of disclosure;

     b.   becomes public knowledge during the term of this Agreement without
fault or involvement by a receiving party;

<PAGE>

     c.   was in a receiving party's possession prior to receipt from a
disclosing party and receiving party is not subject to an existing obligation
of confidence with respect to such INFORMATION;

     d.   is lawfully acquired by a receiving party from a party which is not
subject to an existing obligation of confidence with respect to such
INFORMATION; or

     e.   was developed by employees or agents of a receiving party
independently of and without reference to any INFORMATION received from a
disclosing party.

     Specific INFORMATION disclosed by one party to the other shall not be
deemed to come under the above exemptions merely because it is embraced by
more general information which is or becomes subject to the above exceptions.
To the extent that INFORMATION disclosed hereunder comes under any of the
exceptions referred to above, a receiving party will not disclose that such
INFORMATION was acquired from disclosing party.

     4.   With regard to SAMPLES received, directly or indirectly, by one
party from the other, and unless otherwise authorized in writing by a
disclosing party, a receiving party agrees as follows:

     a.   not to analyze or have analyzed any of the SAMPLES in order to
determine the physical characteristics or chemical composition of any SAMPLES,
except as authorized by a disclosing party;

     b.   not to provide SAMPLES to parties not subject to this Agreement;

     c.   to use the SAMPLES only for the above-stated purposes;

     d.   upon completion of a receiving party's evaluation and unless
otherwise agreed, the receiving party shall return all used and unused
SAMPLES to the disclosing party or recycle or dispose of compositions in
which they are incorporated in a manner to be safeguarded against analysis;
and

     e.   ENGELHARD and HBT shall provide each other with the results of each
party's evaluation of other party's SAMPLES.

     5.   The parties agree that INFORMATION and/or SAMPLES received from
another party will be provided to their respective employees on a
need-to-know basis and warrant that their respective employees who have
access to the INFORMATION and/or SAMPLES received from another party
hereunder are under written obligation of sufficient scope to obligate such
employees to comply with the terms and conditions of this Agreement, but in
any event each party will remain responsible for any breach of this
agreement by their respective employees.

     6.   Within thirty (30) days of a request by one party, the other
parties shall return all INFORMATION, including any copies thereof.

<PAGE>

     7.   In the event that a party is required to disclose INFORMATION or
SAMPLES or results which a party is obligated to maintain in confidence under
this Agreement to a party not subject to this Agreement in response to a
subpoena or order of a court or administrative agency, the party required to
disclose shall inform the other parties promptly so that the other parties
shall have the opportunity to seek a protective order and, provided, that
party required to disclose shall not interfere with the other parties' lawful
efforts to obtain said protective order.

     8.   Nothing contained herein shall be construed as granting any
intellectual property rights except as expressly provided herein.

     9.   Nothing in this Agreement shall be construed as obligating any
party to enter into a business arrangement with another. Any such arrangement
and the terms and conditions thereof shall be agreed upon separately.

    10.   Nothing in this Agreement shall preclude any party from entering
into a similar relationship with any party not subject to this Agreement.

    11.   The term of this agreement shall commence on the Effective Date and
shall terminate on December 31, 2001, but may be extended for an additional
fixed period by written agreement signed by all parties. Any party may
terminate this Agreement upon ninety (90) days written notice to the other
parties.

    12.   Warranties, unless agreed otherwise:

          12.1  Each of the parties provides the INFORMATION and SAMPLES "AS
IS". Each party specifically disclaims the implied warranties of
merchantability and fitness for a particular purpose. Each party is under no
obligation to maintain, correct, update, change, modify, or otherwise support
the SAMPLES.

          12.2  Each of the parties makes no representations or warranties
relating to and expressly disclaims all liabilities for any infringement of
patents, copyrights, or other intellectual property rights of any third
party, which may arise through use of the same INFORMATION and SAMPLES.

     13.  This Agreement constitutes the entire understanding between the
parties hereto with respect to the subject matter indicated above and its
terms may not be changed or amended except by an instrument in writing.


<PAGE>

     IN WITNESS WHEREOF, the parties have caused this Agreement to be
signed in duplicate by their duly authorized representatives.



ENGELHARD CORPORATION       [SEAL]        HYDROGEN BURNER TECHNOLOGY, INC.

By /s/ Daniel W. Parker                    By /s/ David Moard
   -------------------------------            -------------------------------
   Daniel W. Parker                        Name   David Moard
   Group Vice President                    Title  President
   Separation Systems and
   Ventures



<PAGE>


EXHIBIT C.  PROJECT INTELLECTUAL PROPERTIES
<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------------
 ITEM                 DESCRIPTION OF IMPROVEMENT             INITIATING PARTY                OWNERSHIP              DATE SUBMITTED
------------------------------------------------------------------------------------------------------------------------------------
<S>    <C>                                             <C>                           <C>                           <C>
01     Engelhard has filed a patent application                 Engelhard            Engelhard - Sole Not Joint           9-99
       covering the use of our proprietary
       selective oxidation catalyst for CO
       removal in fuel processors on a
       monolith and operating conditions to
       achieve satisfactory conversions of CO
       under realistic fuel processing conditions.

------------------------------------------------------------------------------------------------------------------------------------

02     HBT is preparing a patent application           Hydrogen Burner Technology    Hydrogen Burner Technology    To Be Filed 11/99
       covering the physical hardware and                                                 - Sole Not Joint
       process chemistry related to the UOB
       -Registered Trademark- based fuel-flexible,
       fuel processor (F(3)P) design
       configuration developed and demonstrated
       over the period 1997-1999. This hardware
       and process is the configuration that
       was modified and used for the initial
       two Plug Power hardware deliverables.

------------------------------------------------------------------------------------------------------------------------------------

03     HBT has prepared a patent disclosure that       Hydrogen Burner Technology    Hydrogen Burner Technology    Defined 1997 and
       covers the use and implementation of                                               - Sole Not Joint          documented 1/99
       electrochemical reaction to concentrate
       and/or generate oxygen and thereby control
       rate of introduction into preferential
       CO reactor chambers or catalyst surfaces.

------------------------------------------------------------------------------------------------------------------------------------

04     HBT has prepared a patent disclosure that       Hydrogen Burner Technology    Hydrogen Burner Technology    Defined 1998 and
       covers a process configuration for                                                 - Sole Not Joint          documented 1/99
       distributing fuel processor product gas to
       a series of fuel cell modules. The
       configuration and distribution process allows
       for enhanced tolerance to CO concentration by
       the fuel cell.

------------------------------------------------------------------------------------------------------------------------------------

05     HBT has prepared a patent disclosure that       Hydrogen Burner Technology    Hydrogen Burner Technology    Defined in 1998
       covers the use of pulsed oxygen                                                    - Sole Not Joint          and documented
       addition to preferential oxidation reactors                                                                    1/99 and
       (either through the dual bed configuration                                                                   modified 10/99
       or through the use of pulsed air addition
       to a continuous flow reactor bed). This
       concept of controlled pulsing the air
       feed is potentially applicable to
       the ATR section of the fuel processor.

------------------------------------------------------------------------------------------------------------------------------------

06     HBT used a reverse flow hardware                Hydrogen Burner Technology    Hydrogen Burner Technology    Defined in 10/98,
       configuration for orientation of monolith                                          - Sole Not Joint          implemented in
       catalyst sections that may constitute                                                                           6/99 and
       intellectual property. This configuration                                                                    application is
       takes the reaction gas first through a                                                                         preparation
       extremely high space velocity center core
       followed by a forced mixing against a
       physical wall of the reactor. These gases
       then enter a low space velocity CPO that is
       in turn followed by SMR catalyst sections.
       These catalyst sections are integrated into
       a ATR reactor core that is easily adapted to
       the hardware configuration of the F(3)P
       assembly.

------------------------------------------------------------------------------------------------------------------------------------

07     HBT has defined a anode-gas oxidizer (AGO)      Hydrogen Burner Technology    Hydrogen Burner Technology    Defined in 1998,
       that uses catalyzed finned tubes                                                   - Sole Not Joint          implemented in
       to enhance the direct transfer of heat                                                                 1998/1999 and
       generated by the exothermic reaction to the                                                                 being applied for
       internal endothermic vaporization reaction                                                                  in item 02 above.
       inside the tubes.

====================================================================================================================================
</TABLE>