P-doping optimized electronic metal-support interaction in Os/WC boosts H* transfer for enhanced alkaline hydrogen evolution

• • Overpotentials of 20 mV (alkaline), 51 mV (acidic), and 11 mV (alkaline seawater) at 10 mA cm−2 establish Os/P-WC as a pH-universal HER catalyst, directly challenging Pt/C benchmarks (typically 30–50 mV in alkaline) and enabling deployment in seawater electrolysis without pre-treatment. • • 100-hour chronopotentiometry at both 10 and 500 mA cm−2 in alkaline electrolyte demonstrates operational durability under industrially relevant current densities, addressing the critical failure mode of Pt-based catalysts under prolonged high-current operation. • • Microwave-plasma synthesis in 60 seconds achieves uniform Os nanocluster deposition on P-doped WC, reducing precious metal loading and synthesis time by orders of magnitude compared to conventional furnace methods (hours), directly impacting catalyst manufacturing cost and scalability. • • In-situ Raman, EIS, and HBE experiments confirm that P-doping modulates the electronic metal-support interaction (EMSI), generating electron-enriched Os sites that optimize H* adsorption/desorption and water dissociation, providing a mechanistic basis for designing low-noble-metal catalysts with enhanced kinetics.