Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (09): 2417-2421.doi: 10.3866/PKU.WHXB20100915

• CATALYSIS AND SURFACE STRUCTURE • Previous Articles     Next Articles

Raman Spectroscopic Study on the Solid-State Reaction of V2O5/CeO2 Catalyst

WU Yan-Ni1, GUO Ming1, CHEN Fang2, LUO Meng-Fei1   

  1. 1. Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, Zhejiang Province, P. R. China;
    2. Institute of Catalysis, Zhejiang University, Hangzhou 310028, P. R. China
  • Received:2010-03-31 Revised:2010-05-19 Published:2010-09-02
  • Contact: LUO Meng-Fei E-mail:mengfeiluo@zjnu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20873125).

Abstract:

We prepared V2O5 /CeO2 catalysts with different V2O5 loadings (5% and 15%) by incipient wetness impregnation. Raman spectroscopy (514 and 325 nmexcitation laser lines), X-ray diffraction (XRD), UV-visible diffuse reflectance spectroscopy (UV-Vis DRS), and N2 adsorption were used to study the solid-state reaction between V2O5 and CeO2. We found that the vanadium oxidation species reacted with ceria and formed a CeVO4 phase on the surface of the sample that was calcined at 300 ℃, and the reaction was promoted at higher temperature. In addition, the absorption at 325 nm is stronger than that at 514 nm for the sample, therefore, 325 nm Raman spectroscopy is more sensitive to surface information than 514 nm Raman spectroscopy. Calcination at low temperature leads to unreacted V2O5 in the pores of CeO2 but this is hindered by CeVO4 on the sample surface. Therefore, the Raman band of V2O5 is present when using the 514 nmexcitation laser line and absent when using the 325 nmexcitation laser line.

Key words: Raman spectrum, V2O5 /CeO2, CeVO4, Phase transformation, Absorbance

MSC2000: 

  • O643