Catalyst design, measurement guidelines, and device integration for H2O2 electrosynthesis from oxygen reduction

The electrosynthesis of H2O2 via a two-electron pathway oxygen reduction reaction (2e− ORR) has emerged as a promising way of carbon-free and on-site production of H2O2. Active and selective electrocatalysts for the 2e− ORR are essential for achieving high O2-to-H2O2 conversion efficiency. In this review, we present the recent progress in the development of 2e− ORR electrocatalysts including Pt-group-metal (PGM) and non-PGM atomically dispersed catalysts and metal-free heteroatom-doped carbons. The impact of the active sites and interface structures on the electrocatalytic process is summarized. Benchmarking of the electrocatalytic activities in terms of O2-to-H2O2 mass activity and site-normalized activity is presented to understand the current status of advancement and to provide an insight into possible future research directions. In addition, some guidelines and pitfalls in typical l…