Ternary PtSnRh–SnO2 nanoclusters: synthesis and electroactivity for ethanol oxidation fuel cell reaction

Abstract

Carbon supported ternary Pt52Sn(36−x)Rh12–SnxO2x electrocatalysts with the average diameter of 2.8 ± 0.5 nm were synthesized using a Polyol process followed by thermal treatment. Several techniques including high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and extended X-ray absorption fine structure (EXAFS) were used to identify the coexistence of homogeneously distributed Pt/Sn/Rh random alloy and non-alloyed SnO2 throughout the catalyst. The Pt52Sn(36−x)Rh12–SnxO2x catalyst showed a superior long-term activity and stability towards ethanol oxidation than the commercial Pt catalyst. Our data of ternary Pt/Sn/Rh catalysts with different chemical compositions and crystalline structures also indicated that the superior performance of Pt52Sn(36−x)Rh12–SnxO2x might result from the electronic effect of the Pt/Sn/Rh random alloy.