Exceptional hydrogen evolution in acid enabled by a multi-function-site complex oxide via atomic-scale hydrogen spillover

Abstract Improving the catalytic efficiency of platinum (Pt) for hydrogen evolution reaction (HER) is crucial for water splitting technologies, and hydrogen spillover has emerged as a new frontier in designing the binary-component Pt/support HER electrocatalysts. However, such binary catalysts always suffer from long reaction pathway, undesirable interfacial barrier, and complicated synthesis processes. Here we report a single-phase complex oxide La2Sr2PtO7+δ as a high-performance HER electrocatalysts in acidic media via a unique atomic-scale hydrogen spillover effect between multifunctional catalytic sites. With insights from theoretical calculations, a possible synergistic mechanism involving the hydrogen spillover channel from OLa site→La-Pt bridge site→Pt site is proposed; namely, the OLa site enriches proton, the La-Pt bridge site with thermo-neutral H* adsorption facilitates the hydrogen spillover and H2 generation, and Pt site favors the final H2 desorption. Benefiting from such unusual phenomenon, the resulting La2Sr2PtO7+δ exhibits an exceptional HER electrode activity with low overpotential of 13 mV at 10 mA cm− 2 and small Tafel slope of 22 mV dec− 1, and significantly enhanced intrinsic activity and durability than commercial Pt black catalyst.