Hydrogen-activating models of hydrogenases

• Many models of hydrogenases are made, but few of them activate hydrogen.
• Hydrogen-activating models are reviewed.
• The mechanism of reactions with hydrogen is illustrated.

Hydrogenases are biological catalysts for hydrogen evolution and activation. While many model complexes of hydrogenases can catalyze the hydrogen evolution reaction, few of them can react with hydrogen. Here we review the hydrogen-activating models of hydrogenases, in particular, [NiFe]- and [FeFe]-hydrogenases. The mechanism of these reactions is described.