Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (6): 1187-1193.doi: 10.3866/PKU.WHXB201404281

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Enhanced Sulfur Resistance of Pt-Pd/CeO2-ZrO2-Al2O3 Commercial Diesel Oxidation Catalyst by SiO2 Surface Cladding

YANG Zheng-Zheng1, YANG Yi2, ZHAO Ming2, GONG Mao-Chu2, CHEN Yao-Qiang1,2   

  1. 1 College of Architecture and Environment, Sichuan University, Chengdu 610064, P. R. China;
    2 Key Laboratory of Green Chemistry & Technology of the Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China
  • Received:2014-03-17 Revised:2014-04-28 Published:2014-05-26
  • Contact: CHEN Yao-Qiang
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21173153), National High-Tech Research and Development Program of China (863) (2013AA065304), and Major Research Program of Science and Technology Department of Sichuan Province, China (2011GZ0035, 2012FZ0008).


In this work, porous SiO2 was added to the Pt-Pd/CeO2-ZrO2-Al2O3 (Pt-Pd/CZA) commercial diesel oxidation catalyst (DOC) to improve its sulfur resistibility. The SiO2/Pt-Pd/CeO2-ZrO2-Al2O3 (SiO2/Pt-Pd/CZA) catalyst was prepared by surface coating porous SiO2 onto the Pt-Pd/CZAmonolithic commercial DOC using a multilayer coating method. The as-prepared catalysts were characterized by scanning electron microscopy (SEM), H2 temperature-programmed reduction (H2-TPR), nitrogen adsorption-desorption, energy-dispersive X-ray (EDX) spectroscopy, and thermogravimetric analysis (TGA). SEM images show that the SiO2 layer is porous and uniformly covers the surface of the catalyst. Nitrogen adsorption-desorption isotherm results imply that the texture properties of the as-added SiO2 are similar to those of the Pt-Pd/CZA catalyst, and hence the specific surface area and pore structure of the Pt-Pd/CZA catalyst do not obviously change upon cladding with SiO2. The H2-TPR results imply that the reduction property of the Pt-Pd/CZA catalyst is not obviously affected by surface cladding with SiO2. EDX spectroscopy and TGA results demonstrate that the formation and accumulation of sulfur-contained species on the Pt-Pd/CZA catalyst are suppressed by the SiO2 surface coating. Finally, the as-prepared SiO2/Pt-Pd/CZA catalyst efficiently retained its high catalytic performance and improved the sulfur resistance of the Pt-Pd/CZA commercial DOC.

Key words: Diesel oxidation catalyst, Sulfur resistance, Monolithic catalyst, Multilayer coating, Vehicle exhaust