Electrocatalytic activity of ordered intermetallic PtSb for ethanol electrooxidation

Ordered intermetallic PtSb was synthesized by arc-melting and then sintering treatment. The electro-oxidation of liquid ethanol on PtSb was investigated at room temperature by cyclic voltammetry and chronoamperometry. The results were compared with those at a polycrystalline platinum electrode surface. It was found that at the PtSb surface the onset potential for ethanol oxidation was shifted negatively over 200 mV and the current density at PtSb electrode was about six fold as that at Pt electrode. XRD and XPS technologies were used to investigate the crystal structure and electron effect. The results of electrochemical test and ex-site FT-IR test suggested that ethanol decomposition on PtSb favors the reactive intermediate route and the CO intermediate has less effect on PtSb than on Pt. Part of the dynamic parameters of the electrocatalytic oxidation of ethanol on Pt and PtSb electrodes were obtained through the cyclic voltammetry of different scanning speed. The electron exchange coefficient (alpha) for C2H5OH oxidation on PtSb electrode was much higher than that on Pt electrode.