Preparation of a thin-film Pt electrocatalyst by MnO2 electrodeposition and galvanic replacement reaction for oxidation of methanol

摘要

A MnO2 film is electrodeposited on a gold modified glassy carbon electrode (Au/GCE), Mn(OH)(2) is obtained after electroreduction of MnO2 under alkaline condition, and then the galvanic replacement reaction (GRR) between Mn(OH)(2) and K2PtCl4 yields a thin-film Pt modified electrode (Pt-M(n-GRR)/Au/GCE). The Pt-M(n-GRR)/Au/GCE has high platinum utilization for high-performance oxidation of methanol in both acidic and alkaline media. The peak current densities obtained by cyclic voltammetry in 0.5 M NaOH +1 M CH3OH (-0.8 V similar to 0.8 V, 50 mV/s) and 0.5 M H2SO4 + 1 M CH3OH (-0.2 V similar to 1.0 V, 50 mV/s) are 30.2 and 5.44 mA/cm(pt)(2), respectively, being superior to the control electrodes and many reported electrodes.