Time-Dependent ("Mechanical"), Nonbiological Catalysis. 2. Highly Efficient, "Biomimetic" Hydrogen-Generating Electrocatalysts
The two-electron reduction of inorganic acids (Hp) to hydrogen gas (H2) is efficiently catalyzed by the hydrogenase enzymes in biology . However, the best nonbiological, heterogeneous catalyst is Pt metal, which serves as the universal standard for electrochemical potentials in the Normal Hydrogen Electrode (NHE). A longstanding research goal in the catalysis of multielectron redox processes involving small gaseous molecules like O2, H2, and N2 has been to discover molecular catalysts whose activity exceeds that of the best available heterogeneous catalyst and approaches that of the relevant enzymes .