Palygorskite promoted PtSn/carbon catalysts and their intrinsic catalytic activity for ethanol oxidation

PtSn nanoparticles deposited on a stable electrocatalytic support containing conventional carbon and palygorskite are prepared using pre-treated palygorskite and are evaluated by ethanol oxidation. The electrocatalysts are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). TEM and XRD show that the pre-treatment has an effective impact on the morphology of palygorskite, but does not destroy its architecture. XPS results imply that introduction of palygorskite can facilitate the formation of Sn oxides on the surface of catalyst. Sn oxides increase the amount of surface oxygen-containing species and in turn facilitate to oxidize CO-like species adsorbed on Pt active sites, which has been proved by CO stripping voltammetry. Cyclic voltammetry (CV) measurements show that the addition of palygorskite into the carbon as support improves the electrocatalytic activity in ethanol oxidation. The developed new composite support is catalytically more active for ethanol electrooxidation than the conventional carbon support and shows good stability, offering great potential for widespread application of palygorskite as support for electrocatalysis. (C) 2012 Elsevier Ltd. All rights reserved.