Interfacial hydrogen spillover on Pt/C3N4 enables industrial-level alkaline hydrogen evolution reaction

Hydrogen spillover provides a powerful route to overcome hydrogen binding ability and sluggish water dissociation kinetics in alkaline hydrogen evolution reaction (HER). Here, we present a catalyst with Pt nanoparticles supported on a nonmetallic support (C 3 N 4 ), which achieves efficient hydrogen evolution kinetics and exceptional stability through the hydrogen spillover effect. Density functional theory (DFT) calculations reveals that strong Pt N coordination induces interfacial electron transfer from Pt to C 3 N 4 , establishing a vertical interfacial electric field that drives hydrogen spillover. As a result, Pt/C 3 N 4 –500 delivers industrial-level current densities of 500 and 1000 mA cm −2 at ultralow overpotentials of 89.8 ± 1.5 and 137.7 ± 2.1 mV, respectively, in a three-electrode system. It also maintains stable operation at 500 mA cm −2 for 300 h with a minimal potential variation of just 42.2 mV. In situ electrochemical impedance spectroscopy, in situ Raman spectroscopy, and DFT calculations reveal that the C 3 N 4 support optimizes the kinetics of H 2 desorption (0.8 × 10 −4  s), induces a hydrogen spillover effect, and facilitates the transfer of H* intermediates to the C 3 N 4 (0.37 eV) surface for desorption via low Δ G H⁎ (−0.04 eV) at the interfacial Pt sites. Anion exchange membrane water electrolyzers (AEMWE) using Pt/C 3 N 4 –500 as the cathode requires only 1.73 ± 0.02 V to achieve a current density of 1 A cm −2 and operates stably for over 150 h at 1 A cm −2 .