Rational design and mechanistic elucidation of Pt-based alloy-supported Fe 1 (OH) 3 interfaces for superior CO oxidation catalysis

site. Alloying the Pt support with Cu, Zn, Ag, or Au leads to more exothermic *COOH formation and enhances the reaction kinetics by lowering the kinetic barriers. Electronic analysis reveals that the cohesive energy of the dopant metal and the number of unpaired d-electrons serve as key descriptors for *CO adsorption strength. This work provides a comprehensive design strategy and fundamental insights for developing highly active and stable single-site catalysts for CO oxidation in PEMFCs.