Boosting the interfacial hydrogen migration for efficient alkaline hydrogen evolution on Pt-based nanowires

Abstract

The alkaline hydrogen evolution reaction (HER) on Pt-based catalysts is largely retarded by the insufficient supply of dissociated hydrogen (*H) on Pt sites. Hydrogen spillover offers a promising solution to deliver reactive *H; however, the hydrogen migration process generally suffers from thermodynamic/kinetic obstacles. Herein, we demonstrate that hydrogen spillover on binary PtNi nanowires can be thermodynamically and kinetically boosted by P-doping, resulting in a substantially improved alkaline HER. A combination of experimental and theoretical investigations suggests the dual roles of the incorporated P heteroatoms in facilitating the hydrogen spillover, involving the increased *H coverage by promoting the water dissociation and the accelerated hydrogen migration across the Pt–Ni interface to the Pt sites by lowering the kinetic barrier. Benefiting from the enhanced *H supply on the Pt sites, the P-doped PtNi nanowires exhibit impressive alkaline HER performance (η₁₀ = 12 mV, mass activity = 5.8 A mg_Pt⁻¹ at 70 mV), outperforming most other state-of-the-art HER electrocatalysts.