Kirkendall Effect‐Driven Interface Engineering Facilitates Water Dissociation for Dual‐Site H₂O₂ Electrosynthesis Simultaneously at the Anode and Cathode

Abstract The direct integration of renewable energy into H 2 O 2 electrosynthesis systems offers a promising strategy to minimize energy losses and costs. Due to the intermittency of renewable energy, the dual‐site catalysts must efficiently enable both the two‐electron oxygen reduction reaction (2e − ORR) and water oxidation reaction (2e − WOR). The Kirkendall effect was employed to engineer interfaces and construct a NiZnO x ─C catalyst with exposed (100) facets. The hetero‐cluster NiO x induces oxygen vacancies and built‐in electric fields, which facilitate water activation and subsequent formation of hydrogen and hydroxyl radicals, thereby enabling a single catalyst to rapidly electrosynthesize H 2 O 2 at both the anode and cathode. Notably, 2e − ORR on the cathode enabled rapid synthesis of high‐concentration H 2 O 2 (33987 mg L −1 , 33.18 mol g catalyst −1 h −1 ). NiZnO x ─C achieves stable 2e − ORR/WOR coupling in a continuous‐flow reactor, operating reliably for 4 h under simulated alternating current (AC) and peaking at a total Faradaic efficiency of 150.9% under amperage‐level direct currents. This work provides insights into interface engineering based on the Kirkendall effect, demonstrating the feasibility of directly integrating intermittent renewable energy into H 2 O 2 electrosynthesis systems.