Gas-diffusion and Direct-electron-transfer-type Bioanode for Hydrogen Oxidation with Oxygen-tolerant [NiFe]-hydrogenase as an Electrocatalyst

Abstract

Abstract A membrane-bound [NiFe]-hydrogenase (MBH) from Hydrogenovibrio marinus allows the direct-electron-transfer (DET)-type bioelectrocatalysis for H2 oxidation and is an O2-tolerant promising enzyme for the construction of enzymatic H2–O2 biofuel cells. However, the oxidative and reversible inactivation called “anaerobic inactivation” limits the H2 oxidation at high potentials. In order to avoid this inhibition, we have constructed an MBH-adsorbed gas-diffusion-type electrode, in which H2 is spontaneously supplied to the electrode from the gas phase.