Electrode catalysis versus enzyme catalysis: Theoretical modeling of a biological enzyme

Abstract

Biological enzymes naturally catalyze many important charge transfer and redox reactions that occur in the electrode surface. This is the case of [Ni-Fe] and [Fe-Fe] hydrogenases, which catalyze one of the simplest redox reactions in nature, the reversible two-electron oxidation of H2. These enzymes provide, thence, a way to use H2 as a “clean fuel.” For the reductive process, the ideal source of hydrogen is water that can, for example, be split electrolytically using electricity from renewable, nonfossil energy sources. In nature, green plants can do it, and some bacteria (photosynthetic microorganisms) also contain the enzyme hydrogenase to further convert the released protons into dihydrogen.