Platinum-Ruthenium Single Atom Alloy as a Bifunctional Electrocatalyst toward Methanol and Hydrogen Oxidation Reactions.

Abstract

The precise regulation for the structural properties of nanomaterials at the atomic scale is an effective strategy to develop high-performance catalysts. Herein, a facile dual-regulation approach was developed to successfully synthesize Ru1Ptn single atom alloy (SAA) with atomic Ru dispersed in Pt nanocrystals. High-angle annular dark-field scanning transmission electron microscopy and X-ray absorption fine structure demonstrated that Ru atoms were dispersed in Pt nanocrystals as single atoms. Impressively, the Ru1Ptn-SAA exhibited an ultrahigh specific activity (23.59 mA cm-2) and mass activity (2.805 mA/μg-PtRu) for methanol oxidation reaction (MOR) and exhibited excellent exchange current density activity (1.992 mA cm-2) and mass activity (4.71 mA/μg-PtRu) for hydrogen oxidation reaction (HOR). Density functional theory calculations revealed that the introduction of Ru atoms greatly reduced the reaction free energy for the decomposition of water molecules, which promoted the removal of CO* in the MOR process and adjusted the Gibbs free energy of hydrogen and hydroxyl adsorption to promote the HOR. Our work provided an effective idea for the development of high performance electrocatalysts.