Ultrafine PtRh-Co3O4 ternary alloy nanoparticles with enhanced electrocatalytic activity and long-term stability for alcohol electro-oxidation

Abstract

To date, the development of structure-sensitive electrocatalysts is crucial, consisting of oxophilic metals and a conductive support with Pt-rich surfaces. In this study, PtRh-Co3O4 ternary alloy nanoparticles (similar to 2-3 nm) were uniformly distributed on carbon (PtRh-Co3O4/C) via a co-chemical reduction method. The chemical inertness and oxophilicity of Rh, along with the abundant oxygen defects of Co3O4, contributed to improving the kinetics of the methanol oxidation reaction (MOR) and ethanol oxidation reaction (EOR) in PtRh-Co3O4/ C by promoting the scission of C-C and C-H bonds. PtRh-Co3O4/C displayed high intrinsic activity for both MOR (6.8 mA/cm2Pt) and EOR (3.17 mA/cm2Pt) due to the strong electronic, ligand, and bifunctional effects. Even after 7000 potential cycles, it retained 81% (MOR) and 84% (EOR) of its initial value, indicating extended stability. Compared to other Pt-based benchmark catalysts, PtRh-Co3O4/C exhibited higher CO tolerance, extended activity, and stability, making it a promising electrocatalyst with competitive performance for alcohol electro-oxidation.