Chinese Journal of Catalysis ›› 2013, Vol. 34 ›› Issue (5): 889-897.DOI: 10.1016/S1872-2067(12)60581-6

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Dynamic structural changes of perovskite-supported metal catalysts during cyclic redox treatments and effect on catalytic CO oxidation

GAO Kanga, WEI Mingmingb, QU Zhenpinga, FU Qiangb, BAO Xinheb   

  1. a Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, Liaoning, China;
    b State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China
  • Received:2013-01-05 Revised:2013-05-20 Online:2013-05-06 Published:2013-05-06
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21222305, 20923001) and the National Basic Research Pro-gram of China (973 Program, 2013CB834603, 2013CB933100).

Abstract:

CaTiO3-and BaTiO3-supported Ag and Pt catalysts were subjected to cyclic oxidation and reduction treatments and their surface structures were investigated using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The CO oxidation reactions over the Ag and Pt catalysts showed that the oxidized Ag/oxide catalysts performed better in CO oxidation than the reduced ones did, whereas the reduced Pt/oxide catalysts had higher CO oxidation activity than that after oxidation treatment. The XRD and XPS measurements revealed that the oxidation treatment helped to improve the dispersion of Ag nanoparticles, but their metallic state was retained, which enhanced CO oxidation. In contrast, the surfaces of the Pt nanoparticles were dominated by PtO2 after the oxidation treatment, which lowered the CO oxidation activity compared with that of the reduced Pt catalyst.

Key words: Perovskite oxide, Silver, Platinum, Redox treatment, Structural modification, Carbon monoxide oxidation