Enhancing hydrogen oxidation reaction kinetics of platinum surfaces by intermediates spillover

The sluggish hydrogen oxidation reaction (HOR) of Pt-based catalysts in alkaline conditions necessitates high Pt loadings for desirable performance in the anion exchange membrane fuel cells (AEMFCs). In this study, we leverage the intermediates spillover to decouple elemental steps into two active sites during HOR. In situ spectroscopy characterizations and theoretical calculations reveal that the Pt sites preferentially activate H₂ molecules to form H* intermediates, which could migrate to adjacent W sites with stronger OH* adsorption, where they are further oxidized to H₂O. Consequently, the catalyst demonstrates high performance when integrated into an AEMFC as the anode, achieving a high peak power density of 1.41 W cm⁻² and 1.05 W cm⁻² under H₂-O₂ and H₂-air conditions with a low loading (0.1 mg_Pt cm⁻²), respectively, significantly surpassing that of a Pt/C anode. This study provides possibilities for the rational design of the HOR catalysts via utilizing the intermediates spillover.