Recent Advances with Biomass-Derived Carbon-Based Catalysts for the High-Efficiency Electrochemical Reduction of Oxygen to Hydrogen Peroxide

Abstract

The oxygen reduction reaction (ORR) plays a pivotal role in electrochemical energy conversion and chemical production. Two-electron (2e−) charge transfer for oxygen reduction is considered a promising method for the on-site production of hydrogen peroxide (H2O2), which requires electrocatalysts with high H2O2 selectivity and ORR activity. Noble metal alloys (e.g., Pt-Hg and Pd-Hg) have been prevalent materials of choice due to their desirable intrinsic activity, but their scarcity and high cost seriously hinder their widespread application in practice. Self-doped heteroatomic carbon-based electrocatalysts, derived from abundant and inexpensive biomass, have emerged as attractive candidates for on-site H2O2 production. This review summarizes the fundamentals and recent advances in H2O2 production via 2e− ORR, including basic catalytic mechanisms, the influence of electrolyte pH and porous structure of catalysts, selectivity assessment methods, determination of the cumulative H2O2 concentration, development of biomass-derived carbon-based catalyst, and electrochemical device designs. Current challenges and proposed opportunities are also presented with an emphasis on large-scale electrochemical H2O2 synthesis.