Keliang Wang,Hui Wang,Sivakumar Pasupathi,Vladimir Linkov,Shan Ji,Ronfang Wang
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.
Jian Shi,Jialin Li,Hui Ma,Donghuai Tu,Qian Zhang,Wei Mao,Jianming Yang,Jian Lu
RuO 2 supported on rutile TiO 2 or SnO 2 has been proved extremely effective for catalyzing the oxidation of HCl into Cl 2 . The supports play a crucial role in the catalyst systems. In this work, Ti-Sn oxides with different Sn/(Sn + Ti) molar ratios (0–0.2) were synthesized by a facile co-precipitation method as supports. The corresponding Ru/Ti-Sn oxide catalysts were investigated in HCl catalytic oxidation and systematically characterized to elucidate the role of Ti-Sn oxide supports on the process. The diffraction, spectroscopy and microscopy results reveal the crystal and surface structures of supports and catalysts. Among all the RuO 2 /Ti 1-x Sn x O 2 catalysts, RuO 2 /Ti 0.97 Sn 0.03 O 2 exhibits the best catalytic activity of 2.6 g Cl 2 ·g cat -1 ·h −1 with only 0.5% Ru loading and excellent stability on stream. Differed from the previous understanding, Ti 0.8 Sn 0.2 O 2 support containing the most rutile phase shows unsatisfying performance. The excessive Sn content renders more crystal disorder and volatile substrate, inevitably lowering the dispersion and stabilization of RuO 2 active phase. However, moderate Sn addition induces well-dispersed SnO 2 and rutile TiO 2 film, facilitating the dispersion of RuO 2 phase on the support surface with more active oxygen species. A large number of oxygen vacancies on Ti 0.97 Sn 0.03 O 2 can act as an active oxygen reservoir and boost catalytic performance.