Controllable selective anchoring of subnanometric Ru clusters or single-atoms/clusters on tungsten nitride for the hydrogen oxidation

Abstract

The impregnation method in the preparation of metal cluster catalysts typically inadvertently introduces single atoms (SAs) into the substrate. However, the question of whether the introduction of SAs will further improve the catalytic activity of cluster systems for specific reactions such as the hydrogen oxidation reaction (HOR) remains unraveled. Herein, we demonstrate Ru clusters anchored on WN nanowires (Ru_C/WN) show a higher alkaline HOR catalytic activity in comparison with Ru SAs and nanoclusters (NCs)-coupled catalyst anchored on WN nanowires system (Ru_C,S/WN). Notably, the Ru_C/WN exhibits superb intrinsic catalytic activity with a mass-normalized exchange current density of 890 mA mg⁻¹_PGM, which is among the top level of well developed Ru-based HOR catalysts. Both theoretical simulation and experimental investigation suggest that Ru_C/WN owns an optimized H^* and OH^* reaction intermediates for the alkaline HOR, therefore resulting in the excellent intrinsic HOR catalytic performance.