Structure-informed two-electron electrocatalysis for selective redox synthesis

Abstract

Two-electron electrocatalysis has attracted increasing attention because many high-value molecules, including hydrogen peroxide, formate, nitrite, and halogens, correspond to intermediate oxidation states that cannot be obtained efficiently through conventional multielectron electrocatalytic pathways. Achieving selective termination at the two-electron level therefore represents a fundamental requirement for oxidation-state-precise electrosynthesis, yet progress in this field has remained conceptually fragmented since most studies focus on individual reactions or catalyst systems rather than the underlying chemical principles governing two-electron selectivity. This review addresses that gap by establishing a unified framework that connects reaction classes, competing electron-transfer pathways, structural determinants of selectivity, catalyst families, and representative reaction-specific advances across oxygen, carbon dioxide, nitrogen-oxoanion, and halide chemistries. Particular emphasis is placed on how active-site electronic structure, coordination environment, surface and defect chemistry, crystal phase, and interfacial microenvironment collectively determine whether catalytic interfaces terminate reactivity at the two-electron level or proceed toward deeper redox manifolds. By integrating reaction chemistry with materials structural chemistry, this review moves the field beyond reaction-specific observations toward a broader understanding of oxidation-state-precise electrosynthesis. Such a perspective provides a conceptual basis for transferable catalyst design and offers important implications for selective molecular manufacturing and future electrochemical synthesis.