Ru Single Atoms Anchored on Oxygen-Vacancy-Rich ZrO2-x/C for Synergistically Enhanced Hydrogen Oxidation

Abstract

The hydrogen oxidation reaction (HOR) in alkaline media is pivotal for the advancement of anion exchange membrane fuel cells (AEMFCs), and the development of single-atom catalysts offers a promising solution for creating cost-effective, highly efficient HOR catalysts. Although the transition from nanoparticle to single-atom catalysts enhances catalytic activity, the stability of these single-atom sites remains a significant challenge. In this study, a highly active and stable alkaline HOR catalyst is successfully designed by incorporating Ru atoms into ZrO_2-x/C nanoparticles, forming the single atoms catalyst Ru-SA-ZrO_2-x/C. The catalyst exhibits an outstanding mass activity of 6789.4 mA mg_Ru⁻¹ at 50 mV, surpassing the Ru/C catalyst by 67 fold and the commercial Pt/C catalyst by 42.5 fold. Density functional theory (DFT) simulations reveal that the integration of Ru atoms into ZrO_2-x/C optimizes both the hydrogen bonding energy (HBE) and hydroxyl binding energy (OHBE), reducing the toxicity of Ru sites. This research opens a new pathway for the precise design of single-atom and metal nanoparticle hybrids, offering a promising direction for developing highly active electrocatalysts for alkaline HOR applications.