Electrocatalyst design for promoting two-electron oxygen reduction reaction: Isolation of active site atoms

Abstract

Selective two-electron (2 e(-)) pathway oxygen reduction reaction (ORR) has gained prominence for enabling small-scale, on-site electrochemical H2O2 production and has emerged as a promising alternative to the conventional anthraquinone process. The rational design of catalysts that can suppress the competing four-electron pathway ORR is critical. This review highlights catalyst design strategies for promoting the selective 2 e(-) pathway ORR, including alloying with inert metals, partial surface poisoning, and generating atomically dispersed sites. The major results and advances, as well as unresolved challenges are summarized.