Ru Single Atoms Anchored on Oxygen-Vacancy-Rich ZrO_2-x/C for Synergistically Enhanced Hydrogen Oxidation

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.