Dynamic electrochemical investigations of hydrogen oxidation and production by enzymes and implications for future technology

This tutorial review decribes studies of hydrogen production and oxidation by biological catalysts-metalloenzymes known as hydrogenases-attached to electrodes. It explains how the electrocatalytic properties of hydrogenases are studied using specialised electrochemical techniques and how the data are interpreted to allow assessments of catalytic rates and performance under different conditions, including the presence of O-2, CO and H2S. It concludes by drawing some comparisons between the enzyme active sites and platinum catalysts and describing some novel proof-of-concept applications that demonstrate the high activities and selectivities of these 'alternative' catalysts for promoting H-2 as a fuel.