Synthesis of Active Platinum-Silver Alloy Electrocatalyst toward the Formic Acid Oxidation Reaction

Bimetallic Pt-Ag alloy nanoparticles supported on carbon powder were successfully prepared by the coreduction method using N,N-dimethylformamide as a three-functional solvent, ligand, and reductant in an alkaline medium at room temperature. X-ray diffraction analyses confirmed the formation of face-centered cubic crystal Pt-Ag alloy nanoparticles on the carbon powder. Transmission electron microscopy and energy-dispersive X-ray spectrometer results indicated that well-dispersed Pt-Ag particles (2-4 nm) with the controlled composition (1:1) were formed on the carbon support. X-ray photoelectron spectroscopy measurements revealed that 77% of Pt is present in its metallic state. The alloy-dependent catalytic properties of the PtAg/C alloy nanoparticles were analyzed by cyclic voltammetry method through the formic acid electrooxidation reaction. As compared with the commercial carbon-supported Pt, the PtAg/C synthesized by the method developed in this work gave a lower onset potential, lower peak potential, and higher peak current for the formic acid oxidation reaction.