Chinese Journal of Catalysis ›› 2018, Vol. 39 ›› Issue (5): 929-936.DOI: 10.1016/S1872-2067(18)63018-9

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Effective removal of the protective ligands from Au nanoclusters by ambient pressure nonthermal plasma treatment for CO oxidation

Yuan Tana,b, Hua Liua,b, Xiao Yan Liua, Aiqin Wanga, Changjun Liuc, Tao Zhanga,b   

  1. a State Key Laboratory of Catalysis, iChEM(Collaborative Innovation Center of Chemistry for Energy Materials), Gold Catalysis Research Center, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China;
    c Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
  • Received:2017-11-27 Revised:2017-12-27 Online:2018-05-18 Published:2018-04-19
  • Contact: 10.1016/S1872-2067(18)63018-9
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (21476227, 21522608, 21776271), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17020100), the National Key Research & Development Program of China (2016YFA0202801), the Youth Innovation Promotion Association CAS (2014163), and the Department of Science and Technology of Liaoning Province under contract of 2015020086-101.

Abstract:

We used a dielectric barrier discharge (DBD) plasma technique to eliminate the protective ligand of ZnAl-hydrotalcite-supported gold nanoclusters. We used X-ray powder diffraction, ultraviolet-visible spectrophotometry, thermogravimetric analysis, and high angle annular dark-field-scanning transmission electron microscopy characterization to show that the samples pretreated with/without DBD-plasma displayed different performances in CO oxidation. The enhanced activity was obtained on the plasma-treated samples, implying that the protective ligand was effectively removed via the plasma technique. The crystal structure of the plasma-treated samples changed markedly, suggesting that the plasma treatment could not only break the chemical bond between the gold and the protective agent but could also decompose the interlayer ions over the hydrotalcite support. The particle sizes of the gold after DBD-plasma treatment implied that it was a good way to control the size of the gold nanoparticles under mild conditions.

Key words: Gold cluster, Plasma, Supported gold catalyst, Protective ligand, Carbon monoxide oxidation