Hydrogen production under aerobic conditions by membrane-bound hydrogenases from Ralstonia species

作者：Goldet Gabrielle; Wait Annemarie F; Cracknell James A; Vincent Kylie A; Ludwig Marcus; Lenz Oliver; Friedrich Baerbel; Armstrong Fraser A^*

来源：Journal of the American Chemical Society, 2008, 130(33): 11106-11113.

DOI：10.1021/ja8027668

Studies have been carried out to establish the ability of O(2)-tolerant membrane-bound [NiFe] hydrogenases (MBH) from Ralstonia sp. to catalyze H(2) production in addition to H(2) oxidation. These hydrogenases are not noted for H(2)-evolution activity, and this is partly due to strong product inhibition. However, when adsorbed on a rotating disk graphite electrode the enzymes produce H(2) efficiently, provided the H(2) product is continuously removed by rapidly rotating the electrode and flowing N(2) through the gastight electrochemical cell. Electrocatalytic H(2) production proceeds with minimal overpotential - a significant observation because lowering the overpotential (the electrochemically responsive activation barrier) is seen as crucial in developing small-molecule catalysts for H(2) production. A mutant having a high Km for H(2) oxidation did not prove to be a better H(2) producer relative to the wild type, thus suggesting that weak binding of H(2) does not itself confer a tendency to be a H(2) producer. Inhibition by H(2) is much stronger than inhibition by CO and, most significantly, even O(2). Consequently, H(2) can be produced sustainably in the presence of O2 as long as the H(2) is removed continuously, thereby proving the feasibility for biological H(2) production in air.

• 出版日期2008-8-20