Molten Salt-Assisted Construction of Strong Metal−Support Interaction (SMSI) Type Pt-CeO2 Electrocatalyst for Acidic and Alkaline Hydrogen Evolution

Abstract Hydrogen evolution reaction (HER) catalysts play a crucial role in efficient hydrogen production, yet commercial Pt/C catalysts remain limited by their high platinum loading, high cost, and insufficient durability caused by particle agglomeration and Pt loss during long-term operation. Here, we report a grain-boundary-rich CeO2 nanorod-supported Pt catalyst with strong metal−support interaction (SMSI) for highly active and durable hydrogen evolution in acidic and alkaline media. Pt nanoparticles were anchored on CeO2 nanorods rich in grain boundaries through a molten-salt-assisted strategy, forming stable Pt−O−Ce interfacial bonds. The constructed SMSI not only modulates the electronic structure of Pt but also accelerates reaction kinetics by promoting hydrogen spillover. As a result, the Pt−CeO2-GB catalyst delivers excellent HER activity, requiring low overpotentials of only 15.9 mV and 27 mV to achieve 10 mA cm−2 in 0.5 M H2SO4 and 1.0 M KOH, respectively, together with favorable long-term stability in both electrolytes. Mechanistic analysis reveals that the enhanced activity stems from an optimized Pt electronic structure and facilitated interfacial hydrogen spillover, while the improved durability is attributed to robust Pt−O−Ce bonding and strong anchoring of Pt nanoparticles on CeO2-GBs. This work provides an effective strategy for designing low-Pt, cost-effective, and highly stable electrocatalysts for acidic and alkaline water electrolysis.