Synergistic Catalysis of Pt-Based High-Entropy Clusters Coupled with Super-Hydrophilic CeO Enables Efficient Anion Exchange Membrane Water Electrolysis.

Simultaneously enhancing the intrinsic activity and accelerating HO dissociation kinetics is crucial for developing advanced low-Pt electrocatalysts for the alkaline hydrogen evolution reaction (HER). Herein, a low-noble-metal Pt-based high-entropy alloy clusters coupled with super-hydrophilic CeO on porous carbon support (Pt-HEA-cluster/CeO/C) is developed. The optimized Pt-HEA-cluster/CeO/C catalyst exhibits the faster Volmer-Tafel mechanism with an exceptionally low overpotential of 12.3 mV at -10 mA cm in 1.0 m KOH, surpassing the benchmark commercial Pt/C (32.2 mV). When integrated into an anion exchange membrane water electrolysis, the system achieves low cell voltages of 1.74 V at 1 A cm, and can maintain its performance for at least 500 h at an industrial-level current density. Operando spectroscopy and density functional theory calculations reveal that HO preferentially adsorbs on Ce site of CeO, while the interfacial Pt sites in contact with Ce can simultaneously act as efficient active sites for HO dissociation, thus significantly enhancing the sluggish Volmer kinetics via Ce-Pt dual-site synergy. Concurrently, the electronic structure of surface Pt sites is synergistically regulated through the metal bonds in the HEA and interfacial Pt─O─Ce linkage, thus effectively optimizing its hydrogen adsorption free energy. This work establishes a new paradigm in synergistic catalysis between Pt-HEA-clusters and CeO for efficient alkaline HER.