Acta Phys. -Chim. Sin. ›› 1998, Vol. 14 ›› Issue (07): 590 -596 .doi: 10.3866/PKU.WHXB19980704

• ARTICLE • Previous Articles     Next Articles

Characterization of CuO-BaO/SiO2 Catalysts Structure

Yang Ru, Hu Tian-Dou, Liu Tao, Xiang Hong-Wei, Zhong Bing, Xu Yao, Wu Dong   

  1. State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001|Institute of High Energy Physics,Chinese Academy of Sciences,Beijing 100039
  • Received:1997-09-11 Revised:1997-12-29 Published:1998-07-15
  • Contact: Yang Ru

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Abstract:

 The structure of CuO-BaO/SiO2 catalysts and their reduced states has been characterized by means of XRD, XPS and EXAFS. Both the results of XRD and XPS indicate that(topper and barium in CuO-BaO/SiO2 exist in CuO and BaO respectively and the SiO2 support has influence on the structure of CuO. The EXAFS results show that the coordination number and length of Cu-O shell and Cu-Cu shell gradually decrease with the supported content decreasing and the extent of decrease is the largest for low supported content samples. When the supported content exceeds 13.39%, CuO in samples is in crystalline state, when the supported content is smaller or equals 13.39%, CuO in samples is in monolayer dispersion state. In the reduced catalyst samples, only metal copper is detected. With the content of CuO in CuO-BaO/SiO2 decreasing, the length and coordination number of Cu-Cu bond of metal copper on reduced catalyst surface also decrease gradually.

Key words: CuO, BaO, XRD, XPS, EXAFS, Ultrafine SiO2