Chinese Journal of Catalysis ›› 2017, Vol. 38 ›› Issue (9): 1629-1641.DOI: 10.1016/S1872-2067(17)62798-0

• Articles • Previous Articles    

Three-dimensionally ordered macroporous CeO2/Al2O3-supported Au nanoparticle catalysts:Effects of CeO2 nanolayers on catalytic activity in soot oxidation

Baofang Jina, Yuechang Weia, Zhen Zhaoa,b, Jian Liua, Yazhao Lia, Renjie Lia, Aijun Duana, Guiyuan Jianga   

  1. a State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China;
    b Institute of Catalysis for Energy and Environment, Shenyang Normal University, Shenyang 110034, Liaoning, China
  • Received:2016-11-29 Revised:2017-01-07 Online:2017-09-18 Published:2017-09-06
  • Contact: 10.1016/S1872-2067(17)62798-0
  • Supported by:

    This work was supported by the National High Technology Research and Development Program of China (863 Program,2015AA034603),the National Natural Science Foundation of China (21477146,21673142 and 21303263),the Beijing Nova Program (Z141109001814072),the Special-ized Research Fund for the Doctoral Program of Higher Education (20130007120011),and the Science Foundation of China University of Petroleum-Beijing (YJRC-2013-13,2462013BJRC003).

Abstract:

A series of catalysts consisting of three-dimensionally ordered macroporous (3DOM) x-CeO2/Al2O3-supported Au nanoparticles (x=2, 10, 20, and 40 wt%) were successfully synthesized using a reduction-deposition method. These catalysts were characterized using scanning electron microscopy, the Brunauer-Emmett-Teller method, X-ray diffraction, transmission electron micros-copy, ultraviolet-visible spectroscopy, and temperature-programmed reduction by H2. Au nanopar-ticles of mean particle size 5 nm were well dispersed and supported on the inner walls of uniform macropores. The 3DOM structure improved the contact efficiency between soot and the catalyst. An Al-Ce-O solid solution was formed in the multilayer support, i.e., x-CeO2/Al2O3, by the incorporation of Al3+ ions into the CeO2 lattice, which resulted in the creation of extrinsic oxygen vacancies. Strong interactions between the metal (Au) and the support (Ce) increased the amount of active oxygen species, and this promoted soot oxidation. The catalytic performance in soot combustion was eval-uated using a temperature-programmed oxidation technique. The presence of CeO2 nanolayers in the 3DOM Au/x-CeO2/Al2O3 catalysts clearly improved the catalytic activities in soot oxidation. Among the prepared catalysts, 3DOM Au/20%CeO2/Al2O3 showed high catalytic activity and stabil-ity in diesel soot oxidation.

Key words: Three-dimensionally ordered macroporous material, Gold nanoparticle, Multilayer support, CeO2 nanolayer, Soot combustion