Catalase-Based Air-Cathode for Biocompatible Zinc-Air Battery

Abstract

The use of catalase (CAT) from bovine liver as electrocatalyst in the air electrode of a primary zinc-air battery (ZAB) with neutral electrolyte (pH 7.4) is reported. Firstly, the use of Nafion for immobilizing CAT onto electrode surface allowed to obtain long-term stability of the catalytic activity of CAT. Besides, analysis of the CAT and CAT-Nafion as catalysts for oxygen reduction reaction (ORR) was carried by lineal scan voltammetry (LSV) using a rotating ring-disk electrode (RRDE), demonstrating a four-electron ORR mechanism. Finally, CAT and CAT-Nafion were tested as air electrodes in flooded ZAB and compared against Human Hemoglobin based-ZAB. Our results demonstrated the significant influence of the protein coating of the heme groups on the ZAB performance, affecting greatly to the discharge capacity and to the power density.