文献类型：期刊文献

英文题名：The effects of the Pd chemical state on the activity of Pd/Al2O3 catalysts in CO oxidation

作者：Zhang, Yanhui[1];Cai, Yafeng;Guo, Yun;Wang, Haifeng;Wang, Li;Lou, Yang;Guo, Yanglong;Lu, Guanzhong;Wang, Yanqing

机构：[1]E China Univ Sci & Technol, Key Lab Adv Mat, Shanghai 200237, Peoples R China; E China Univ Sci & Technol, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2014

卷号：4

期号：11

起止页码：3973

外文期刊名：CATALYSIS SCIENCE & TECHNOLOGY

收录：;EI(收录号：20144200108704);WOS:【SCI-EXPANDED(收录号:WOS:000343004900023)】；

基金：This project was supported financially by the National Basic Research Program of China (2010CB732300, 2013CB933201), the National High Technology Research and Development Program of China (2012AA062703, 2012AA111717), the NSFC of China (21171055, 21273150), the New Century Excellent Talents in University (NECT-10-0377), the "ShuGuang" Project of Shanghai Municipal Education Commission and Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Fourier series - X ray diffraction - Catalyst supports - Adsorption - Catalyst activity - Fourier transform infrared spectroscopy - Palladium - Alumina - Aluminum oxide - Palladium compounds - Chlorine compounds - X ray photoelectron spectroscopy

摘要：CO adsorption and O-2 activation played important roles in CO oxidation on a supported Pd catalyst, which were dependent on the chemical state of Pd. A series of Pd catalysts supported on Al2O3 with different Pd states were prepared: metal Pd (NCR), PdO (NC), Pd2+ coordinated with Cl-(Pd2+-Cl-, CF), and a mixture of PdO and Pd2+-Cl-(CC) and the activity of CO oxidation was in the order NCR similar to CF > CC >> NC. The catalysts were characterized by Brunauer, Emmett and Teller (BET) surface area analysis, X-ray diffraction (XRD), temperature programmed reduction by hydrogen (H-2-TPR), X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results showed that metal Pd (Pd-0) could be partially oxidized to Pd+ in the presence of O-2, which produced new CO adsorption sites and decreased the CO adsorption strength simultaneously. The cooperation between the enhanced CO adsorption and the decrease in the CO adsorption strength led to high activity for CO oxidation on NCR. For high chemical valence Pd in the species (Pd2+), the chemical environment or coordinated ligand of the Pd species showed large effects on the CO oxidation. The lowest CO oxidation activity on NC occurred when PdO hardly adsorbed CO, meanwhile, PdO was not easily reduced by CO. However, the presence of Cl-significantly promoted the reduction of Pd2+ to Pd+, which increased the amount of CO adsorption and resulted in the higher activity for CO oxidation on CF and CC than PdO. Tuning the CO adsorption by adjusting the chemical state of Pd may be a useful approach to prepare a highly efficient supported Pd catalyst.