Enhancement of Oxidation of Dimethyl Ether Through Utilization of SnO2 for Immobilization of Pt Catalytic Nanoparticles

Abstract Pt/C+SnO 2 nanoparticles catalysts with SnO 2 and Vulcan XC-72 carbon black as the mixed support were synthesized by facile and effective ethylene glycol reduction methods, the effect of SnO 2 with different contents on the performance of Pt/C+SnO 2 catalysts in dimethyl ether electrooxidation and stability were investigated. The catalysts were physically characterized by energy dispersive analysis of X-ray diffraction (XRD), X-ray (EDAX), X-ray photoelectron spectroscopy(XPS) and transmission electron microscopy(TEM). The results showed that Pt nanoparticles had a small size distribution. Moreover, Pt nanoparticles and SnO 2 units were dispersed uniformly on the surface of carbon support. The results of cyclic voltammetry(CV), chronoamperometry(CP), accelerated potential cycling tests (APCT) and electrochemical impedance spectra (EIS) exhibited that Pt/C+SnO 2 catalysts have higher electrooxidation activity and stability than Pt/C catalyst. SnO 2 can adsorb OH ads species, the addition of SnO 2 could be benefit to improve the adsorption of DME on Pt/C+SnO 2 surface and reduce the Pt poisoning effect. When the SnO 2 content in the catalyst attained as high as 20 wt .%, the catalyst shows the greatest activity and stability towards DME oxidation. The excess amount of SnO 2 might give rise to the cover of the active sites of Pt surface, which obstructed the further dimethyl ether electrooxidation.