Acta Phys. -Chim. Sin. ›› 2014, Vol. 30 ›› Issue (2): 351-358.doi: 10.3866/PKU.WHXB201312021

• CATALYSIS AND SURFACE SCIENCE • Previous Articles     Next Articles

Effect of Ce Promoter on Catalytic Performance of V/SiO2 in Oxidative Dehydrogenation of Ethylbenzene with Carbon Dioxide

ZHANG Hai-Xin1, CHEN Shu-Wei1,2, CUI Xing-Yu3, PAN Da-Hai1, QIN Zhang-Feng2, WANG Jian-Guo2   

  1. 1 College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024, P. R. China;
    2 State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, P. R. China;
    3 Institute of Special Chemicals, Taiyuan University of Technology, Taiyuan 030024, P. R. China
  • Received:2013-08-06 Revised:2013-11-29 Published:2014-01-23
  • Contact: CHEN Shu-Wei, CUI Xing-Yu E-mail:csw603@163.com;cuixingyu@tyut.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (51172154), Science and Technology Project of Shanxi Province, China (20130313001-3), Foundation of State Key Laboratory of Coal Conversion, China (J12-13-603), and Shanxi Province Science Foundation for Youths, China (2012021006-2).

Abstract:

The effect of a Ce promoter on the catalytic properties of V/SiO2 was investigated for the oxidative dehydrogenation of ethylbenzene (EB) to styrene (ST) with CO2 (CO2-ODEB). The catalysts were characterized by nitrogen adsorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2 temperature-programmed reduction (H2-TPR), CO2 temperature-programmed desorption (CO2-TPD), and thermogravimetric analyses (TGA). It was found that incorporation of Ce into V/SiO2 increased the dispersion of active V species, enhanced the redox properties of the system, and inhibited deep V reduction of V5+ to V3+ . The Ce promoter also improves the basicity of V/SiO2 and CO2 adsorption on the catalyst, and suppresses coke formation. The addition of a Ce promoter greatly improves the catalytic activity and stability of V/SiO2 towards CO2-ODEB. The ST yield and selectivity reach 55.6% and 98.5%, respectively, for CO2-ODEB over the most efficient catalyst, V(0.8)Ce(0.25)/SiO2, at 550℃, and a CO2/EB molar ratio of 20. Moreover, after reaction for 12 h, the V(0.8)Ce(0.25)/SiO2 still shows stable catalytic activity. The ST yield in CO2 is higher than that in an inert N2 atmosphere, showing the significant promoting effect of CO2 on EB dehydrogenation; this is because CO2 is a soft oxidant and can effectively keep/regain the high valence of V for high activity with CO2-ODEB.

Key words: Cerium oxide, Supported vanadium oxide catalyst, Carbon dioxide, Ethylbenzene dehydrogenation, Styrene

MSC2000: 

  • O643