Interfacial Water‐Regulated High‐Entropy Intermetallic Catalysts for Selective Ethylene Glycol Upgrading and Self‐Powered Hydrogen Production

Selective electrochemical upgrading of ethylene glycol (EG) to glycolic acid (GA) coupled with hydrogen evolution provides a promising pathway for chemical‐energy co‐production, yet remains challenged by CO poisoning, excessive C‐C bond cleavage, and uncontrolled oxygenated intermediates on Pt‐based catalysts. This work develops a platinum‐based high‐entropy intermetallic catalyst (Pt 4 FeCoNiCu) anchored on phosphorus‐nitrogen co‐doped porous carbon (HEI‐PNC) for selective EG oxidation and hydrogen evolution. The ordered intermetallic lattice creates chemically diverse atomic environments that regulate interfacial water structures and oxygenated intermediate evolution during EG oxidation, thereby suppressing CO poisoning and unwanted C─C bond cleavage. Meanwhile, electronic redistribution within the intermetallic lattice stabilizes key C2 intermediates and accelerates reaction kinetics. Consequently, HEI‐PNC delivers a low onset potential of 0.304 V, a 4.4‐fold enhancement in Pt mass activity compared with Pt/C and achieves a glycolate Faradaic efficiency of 98.2%. Integrated into a hybrid alkali/acid fuel cell, the catalyst enables self‐powered co‐production of glycolate and H 2 with stable operation over 220 h. This work highlights interfacial water‐regulated high‐entropy intermetallic catalysis as an effective strategy for selective polyol upgrading and chemical‐energy co‐production.