Preparation of PdPtSn/C-Sb₂O₅.SnO₂ electrocatalysts by Borohydride Reduction for Ethanol Electro-Oxidation in Alkaline Medium

摘要

PdPt/C-Sb2O5.SnO2 (80:20), PdPtSn/C-Sb2O5.SnO2 (80:10:10) and PdPtSn/C-Sb2O5.SnO2 (90:05:05)electrocatalysts were prepared in a single step using H2PtCl6.6H2O, Pd(NO3)2 2H2O and SnCl2.2H2O asmetal sources, sodium borohydride as reducing agent and a physical mixture of 85% Vulcan CarbonXC72 and 15% Sb2O5.SnO2 (antimony tin oxide ATO) as support. The obtained electrocatalystswere characterized by X搑ay diffraction (XRD) and cyclic voltammetry (CV). The activity for theethanol electro-oxidation in alkaline medium was investigated at room temperature by cyclicvoltammetry and chronoamperometry. The electrochemical studies showed that PdPtSn/C-Sb2O5.SnO2(80:10:10) electrocatalyst had superior performance for ethanol electro-oxidation at room temperaturecompared to the other electrocatalysts prepared. Pt/C-ATO, Pd/C-ATO, PdPt/C-ATO and PdPtSn/C- ATO electrocatalysts were also tested for ethanol electro-oxidation in acid medium and the finalcurrent values obtained after holding the cell potential at .4 V for 30 min were compared to the onesobtained in alkaline medium. The results confirmed that Pd-based electrocatalysts are emerging as analternative to Pt-based catalysts for ethanol electro-oxidation in alkaline DEFCs, while that Pt-basedelectrocatalysts are effective for ethanol electro-oxidation in acidic DEFCs.