Thermal and Photocatalytic Production of Hydrogen Peroxide and its Use in Hydrogen Peroxide Fuel Cells

Abstract

This mini review describes our recent developments on the thermal and photocatalytic production of hydrogen peroxide and its use in hydrogen peroxide fuel cells. Selective two-electron reduction of dioxygen to hydrogen peroxide by one-electron reductants has been made possible by using appropriate metal complexes with an acid. Protonation of the ligands of the complexes facilitates the reduction of O2. The photocatalytic two-electron reduction of dioxygen to hydrogen peroxide also occurs using organic photocatalysts and oxalic acid as an electron source in buffer solutions. The control of the water content and pH of a reaction solution is significant for improving the catalytic activity and durability. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Utilisation of iron complexes as cathode materials are reviewed.