PLEDGE AGREEMENT

THIS PLEDGE AGREEMENT (this “ Agreement ”), dated as of August 22, 2008, is made by and between HYDROGEN CORPORATION ,   a Nevada corporation (“the “ Pledgor ”) in favor of FEDERATED KAUFMANN FUND, a portfolio of Federated Equity Funds, a Massachusetts business trust, as agent for the Lenders (as defined below) (in such capacity, together with its successors and assigns, the “ Pledgee ” ).

A.   The Pledgor, Hydrogen, L.L.C., an Ohio limited liability company (the “ Borrower ”), Federated Kaufmann Fund, a portfolio of Federated Equity Funds, a Massachusetts business trust and Samsung C&T Corporation, a corporation organized under the laws of the Republic of Korea (collectively, together with their respective successors and assigns, the “ Lenders ”), and the Pledgee in its capacity as Agent for the benefit of the Lenders are parties to that certain Loan and Security Agreement of even date herewith (as amended, the “ Loan Agreement ”). Capitalized terms used herein but not defined herein shall have the meanings ascribed thereto in the Loan Agreement.

B.   Pursuant to the Loan Agreement, the Lenders are making term loans to the Borrower (the “ Loan” ).

C.   As a condition to the making of the Loan to the Borrower and pursuant to that certain Guaranty, dated as of even date herewith, between the Agent and the Pledgor, the Pledgor is required to execute and deliver this Agreement and shall have made the pledge contemplated hereunder of its membership interest in the Borrower to provide security for the Borrower’s obligations under the Loan Agreement and any and all other instruments, agreements and documents delivered or executed in connection therewith (as any of the foregoing may be amended, supplemented or modified from time to time, collectively, the “ Loan Documents ”).

NOW, THEREFORE , in consideration of the premises hereinabove, and for other good and valuable consideration, the receipt, adequacy and sufficiency of which are hereby acknowledged, the Pledgor hereby covenants and agrees with the Pledgee as follows:

1.   SECURITY FOR OBLIGATIONS, ETC. This Agreement is for the benefit of the Pledgee (in its capacity as Agent for the benefit of the Lenders) and any successor Agents appointed pursuant to the Loan Agreement to secure the prompt and complete payment and performance when due of all obligations, liabilities, indebtedness (whether for principal, interest, charges, or fees), costs, expenses, covenants, indemnities and agreements of every nature whatsoever of the Borrower to the Lenders and the Pledgee (in its capacity as Agent for the benefit of the Lenders) now existing or hereafter arising under the Loan Agreement, this Agreement, and any and all other Loan Documents (all of the foregoing being herein collectively called the “ Secured Obligations ”).

2.   DEFINITION OF PLEDGED COLLATERAL. As used herein, the term “ Pledged Collateral ” shall mean one hundred percent (100%) of Pledgor’s membership interest in the Borrower.

3.   PLEDGE OF PLEDGED COLLATERAL AND OTHER COLLATERAL .

3.1   Pledge . To secure the Secured Obligations and for the purposes set forth in Section 1 hereof, Pledgor hereby pledges, collaterally assigns and conveys, and grants a security interest in and lien on, in favor of Pledgee (as Agent for the benefit of the Lenders), all of Pledgor’s right, title and interest in, to, and under (A) the Pledged Collateral, (B) any additional Pledged Collateral acquired pursuant to Section 3.2 below (whether by purchase, dividend, distribution, merger, consolidation, sale of assets, split, spin-off, or any other dividend or distribution of any kind or otherwise), (C) all distributions, dividends, cash, certificates, liquidation rights and interests, options, rights, warrants, instruments or other property from time to time received, receivable or otherwise distributed in respect of or in exchange or substitution for any and all of the Pledged Collateral, and (D) all proceeds, products, replacements and substitutions for any of the foregoing, in each case whether now owned or hereafter acquired by the Pledgor (collectively, the “ Collateral ”). The Pledgor shall permit the Pledgee to file a UCC Financing Statement naming the Pledgor as debtor and the Pledgee as secured party with respect to the Collateral in any jurisdiction reasonably required by the Pledgee (including with the Nevada Secretary of State).

3.2   Subsequently Acquired Pledged Collateral . If at any time or from time to time after the date hereof, the Pledgor shall acquire any additional Pledged Collateral, including any further equity in the Borrower (whether by purchase, dividend, distribution, merger, consolidation, sale of assets, split, spin-off, or any other dividend or distribution of any kind or otherwise), the Pledgor will forthwith pledge additional Collateral. The Pledgor shall permit the Pledgee to file a UCC Financing Statement naming the Pledgor as debtor and the Pledgee as secured party with respect to the additional Collateral in any jurisdiction reasonably required by the Pledgee (including with the Nevada Secretary of State).

3.3   Certificated Pledged Collateral . In addition to anything contained in Sections 3.1 and 3.2 hereof, if any Pledged Collateral (whether now owned or hereafter acquired) is or becomes evidenced by a certificated security, the Pledgor shall promptly notify the Pledgee thereof and shall promptly take all actions required to perfect the security interest of the Pledgee (as Agent for the benefit of the Lenders) under applicable law (including, in any event, delivery of physical possession of all certificates to the Pledgee, and take any other action required or appropriate under this Agreement or the Uniform Commercial Code of the State of New York or equivalent provisions of any other applicable jurisdiction (the “ UCC ”)).

4.   VOTING, ETC . Unless and until an Event of Default (as defined in the Loan Agreement) occurs, the Pledgor shall be entitled to vote any and all of the Pledged Collateral. All such rights of the Pledgor to vote shall cease in case an Event of Default shall occur and the Pledgee elects to enforce its rights and remedies against the Pledged Collateral and so directs and notifies the Pledgor.

5.   PAYMENTS AND OTHER DISTRIBUTIONS . Unless and until an Event of Default (as defined in the Loan Agreement) occurs, all cash distributions payable in respect of the Pledged Collateral shall be paid to the Pledgor. All such rights of the Pledgor to receive such cash distributions shall cease in case an Event of Default shall occur and the Pledgee elects to enforce its rights against the Pledged Collateral and so directs and notifies the Pledgor. The Pledgee shall be entitled to receive directly, and to retain as part of the Collateral:

(a)   all other or additional securities or investment property, or rights to subscribe for or purchase any of the foregoing, or property (other than cash) paid or distributed by way of dividend in respect of the Pledged Collateral;

(b)   all other or additional securities, investment property or property (including cash) paid or distributed in respect of the Pledged Collateral by way of split, spin-off, split-up, reclassification, combination of shares or similar rearrangement; and

(c)   all other or additional securities, investment property or property which may be paid in respect of the Collateral by reason of any consolidation, merger, exchange, dividend, split, or distribution, conveyance of assets, liquidation or similar reorganization or other disposition of Collateral.

If at any time the Pledgor shall obtain or possess any of the foregoing Collateral described in this Section, the Pledgor shall be deemed to hold such Collateral in trust for the Pledgee and the Pledgor shall promptly surrender and deliver such Collateral to the Pledgee.

6.   REMEDIES IN CASE OF AN EVENT OF DEFAULT . In case an Event of Default occurs or exists, the Pledgee shall be entitled to exercise all of the rights, powers and remedies (whether vested in it by this Agreement, the Loan Agreement, any other Loan Documents, and/or in equity or by law, and including, without limitation, all rights and remedies of a secured party of a debtor in default under the UCC) for the protection and enforcement of its rights in respect of the Collateral, and to the fullest extent permitted by applicable law, the Pledgee shall be entitled, without limitation, to exercise the following rights, which the Pledgor hereby agrees to be commercially reasonable:

(a)   to receive all amounts payable in respect of the Collateral otherwise payable under Section 5 hereof to the Pledgor;

(b)   to transfer all or any part of the Collateral into the Pledgee’s name or the name of its nominee or nominees;

(c)   to vote all or any part of the Collateral and otherwise act with respect thereto as though it were the outright owner thereof;

(d)   at any time or from time to time to sell, assign and deliver, or grant options to purchase, all or any part of the Collateral in one or more parcels, or any interest therein, at any public or private sale at any exchange, broker’s board or at any of the Pledgee’s offices or elsewhere, without demand of performance, advertisement or notice of intention to sell or of time or place of sale or adjournment thereof or to redeem (all of which, except as may be required by mandatory provisions of applicable law, are hereby expressly and irrevocably waived by the Pledgor) for cash, on credit or for other property, for immediate or future delivery without any assumption of credit risk, and for such price or prices and on such terms as the Pledgee in its absolute discretion may determine. Pledgor agrees that to the extent that notice of sale shall be required by law that at least ten (10) calendar days’ notice to the Pledgor of the time (which shall be during normal business hours) and place of any public sale or the time after which any private sale is to be made shall constitute reasonable notification. The Pledgee shall not be obligated to make any sale of Collateral regardless of notice of sale having been given. The Pledgee may adjourn any public or private sale from time to time by announcement at the time and place fixed therefor, and any such sale may, without further notice, be made at the time and place to which it was so adjourned. Pledgor hereby waives and releases to the fullest extent permitted by law any right or equity of redemption with respect to the collateral, whether before or after sale hereunder, and all rights, if any of marshalling the Collateral and any other security for the Secured Obligations or otherwise. At any such sale, unless prohibited by applicable law, the Pledgee may bid for and purchase all or any part of the Collateral so sold free from any such right or equity of redemption. The Pledgee shall not be liable for failure to collect or realize upon any or all of the Collateral or for any delay in so doing nor shall the Pledgee be under any obligation to take any action whatsoever with regard thereto;

(e)   to settle, adjust, compromise and arrange all accounts, controversies, questions, claims and demands whatsoever in relation to all or any part of the Collateral;

(f)   in respect of the Collateral, to execute all such contracts, agreements, deeds, documents and instruments, to bring, defend and abandon all such actions, suits and proceedings, and to take all actions in relation to all or any part of the Collateral as the Pledgee in its absolute discretion may determine;

(g)   to appoint managers, sub-agents, officers and servants for any of the purposes mentioned in the foregoing provisions of this Section and to dismiss the same, all of the Pledgee in its absolute discretion may determine; and

(h)   generally, to take all such other action as the Pledgee in its absolute discretion may determine as incidental or conducive to any of the matters or powers mentioned in the foregoing provisions of this Section and which the Pledgee may or can do lawfully and to use the name of the Pledgor for the purposes aforesaid and in any proceedings arising therefrom.

7.   REMEDIES, ETC., CUMULATIVE . Each right, power and remedy of the Pledgee provided for in this Agreement, the Loan Agreement, any Loan Document or any other security agreement, mortgage, guaranty or