Electrocatalytic Performance of Gold Nanoparticles Supported on Activated Carbon for Methanol Oxidation in Alkaline Solution

Abstract

Gold nanoparticles supported on activated carbon (Au/C) are prepared by rapid reduction of AuCl4− on the surface of activated carbon with KBH4 in the presence of polyvinylpyrrolidone. Through the characterization of the transmission electron microscope, the Au nanoparticles (AuNPs) are highly well dispersed on the carbon support. Cyclic voltammetry, quasi-steady-state polarization, and electrochemical impedance spectroscopy methods are employed to investigate the catalytic activity of the Au/C catalyst for the methanol electro-oxidation (MEO) and the reaction kinetics. The results indicate that the Au/C catalyst shows good catalytic activity toward the MEO, and the weakly adsorbed OH− on the surface of AuNPs has auxiliary catalysis for the MEO. On the basis of this crucially auxiliary catalysis, a novel mechanism of the rate-determining step of the MEO catalyzed by Au/C in alkaline solution is proposed.