Ampere‐Level 4000 h Parallel Alcohols Electro‐Refinery and Hydrogen Production

Abstract Coupling electro‐refinery with water electrolysis paves a sustainable pathway for parallel production of value‐added chemicals and hydrogen. However, its practical feasibility remains hindered by large overpotentials, unsatisfactory selectivity, and inadequate durability. Here, we report a pH‐asymmetric hybrid system of electrolysis (AHSE) to realize ampere‐level, long‐term alcohols electro‐refinery and parallel hydrogen production. By harnessing internal neutralization energy, the AHSE simultaneously produces benzoic acid (Ph‐COOH) and hydrogen at a low electricity expense of 3.19–3.78 kWh per m 3 H 2 at 500 mA cm −2 , saving 24.6–30.6% energy than pH‐symmetric systems. The operational stability is maximized by independent optimization of pH conditions at the anode and cathode, allowing for continuous operation over 4100 h at large current densities of 500–1000 mA cm −2 . High Faradaic efficiency (FE) of 91.3–97.7% is reached for benzyl alcohol (BA) conversion, with 78.5–95.5% Ph‐COOH selectivity. When scaled up 100 folds, the AHSE retains over 85% FE for BA conversion and 88.5% Ph‐COOH selectivity while yielding hydrogen at a fast rate of 18.7 L h −1 at an ultra‐high current of 50 A at 3.14 V.