Microwave-Assisted PtRu Alloying on Defective Tungsten Oxide: A Pathway to Improved Hydroxyl Dynamics for Highly-Efficient Hydrogen Evolution Reaction

Abstract

Platinum (Pt)-based compounds are the benchmarked catalysts for hydrogen evolution reaction (HER) but exhibit slow kinetics in alkaline environments. The ^*OH accumulation on Pt surface can block active sites, affecting proton reduction and water re-adsorption. Alloying Ruthenium (Ru) with Pt sites can significantly modulate the adsorption and desorption of water dissociation intermediates. Choosing suitable supports and utilizing metal-support interaction (MSI) is crucial for active site optimization. PtRu alloy anchored on tungsten oxide (WO₃) with rich oxygen vacancies (O_V) is prepared through an ultrafast microwave-assisted approach. Benefiting from the coupling effects between alloying and MSI, PtRu/WO₃-O_V exhibits exceptionally high HER activity. In 1 m KOH, 1 m KOH + seawater, and 0.5 m H₂SO₄, it requires ultralow overpotentials of 9, 26, and 6 mV to achieve 10 mA cm⁻², respectively. The designed catalyst surpasses commercial Pt/C in mass activity and demonstrates considerable potential for intermittent energy integration. Density functional theory reveals that alloying Ru with Pt sites significantly reduces the energy barrier of dissociating ^*OH, modulating blockage on the surface and then promoting the overall alkaline HER process. This study offers insights into the rapid synthesis of non-carbon supported catalysts with Pt site modulation for alkaline hydrogen generation.