Electron‐Rich Ru Clusters Anchored on Pure Phase W2C Enables Highly Active and CO‐Resistant Alkaline Hydrogen Oxidation

The charge transfer from the pure phase W₂C to the strongly anchored Ru clusters significantly alters the electronic structure of the Ru sites, which has a profound effect on the adsorption properties and reaction kinetics of the key reaction intermediates, thereby exhibiting a highly active and anti-CO poisoning catalyst in alkaline hydrogen oxidation reaction.

Abstract

Developing highly active and CO-resistant Ru-based catalysts for the alkaline hydrogen oxidation reaction (HOR) can advance the large-scale application of alkaline hydrogen fuel cells but remains a huge challenge. Herein, a pure phase W₂C supported Ru cluster catalyst (Ru/W₂C) is successfully synthesized through a one-step carburization method. It is found that the charge transfer from W₂C to the strongly anchored Ru clusters forms the electron-rich Ru^δ− sites and electron-deficient W^δ+ sites, which significantly weakens the adsorption strength of ^*H and ^*CO, strengthens the binding of ^*OH and improves the water connectivity in the electric double layer. The Ru/W₂C catalyst shows superior mass activity (2163 mA mg_PGM ⁻¹) in alkaline HOR, which is 12.52 and 20.62 times higher than that for Pt/C and Ru/C, respectively. Owing to the weak adsorption and fast removal rate of CO, the Ru/W₂C exhibits outstanding CO tolerance, with 88% of the initial activity being retained in the durability test, whereas the Ru/C and Pt/C suffer from severe deactivation. These findings may guide the design of advanced alkaline HOR catalysts based on the pure phase tungsten carbide.