Dynamic Decoupling as a Strategy for Highly Selective H2O2 Electrosynthesis

Electrochemical H2O2 synthesis via the 2e- oxygen reduction reaction (ORR) is a promising sustainable alternative to conventional industrial production. Nonetheless, its practical efficiency is fundamentally capped by the inherent coupling of catalytic kinetics, interfacial electric field, and mass transport, becoming a critical bottleneck for classical static electrolysis strategies. Here, a dynamic decoupling strategy (i.e., a temporal separation of the dominant interfacial constraint rather than a physical decoupling of involved processes) is introduced and validated on a Co-ONx-C single-atom-catalyst-based cathode, employing pulsed electrolysis to modulate the coupled processes in the time domain. This dynamic approach engineers the electrocatalytic interface through three time-separated effects of unequal weight: mass-transport replenishment during the rest interval predominantly enhances H2O2 accumulation, interfacial-field modulation across the potential of zero charge governs the selectivity improvement, and support-defect modulation enables efficient Co-site utilization. As a result, this unconventional approach promotes a 2.7-fold enhancement of H2O2 concentration over the static mode, significantly suppressing the parasitic H2 evolution reaction. Validated in a photovoltaic-driven system with over 100 day stable production, this work establishes dynamic decoupling as a smart design principle for next-generation environmental electrocatalysis.