Acta Phys. -Chim. Sin. ›› 2003, Vol. 19 ›› Issue (06): 519-522.doi: 10.3866/PKU.WHXB20030608

• ARTICLE • Previous Articles     Next Articles

Monolayer Dispersive CuO/γ-Al2O3 Catalyst Studied by XAFS

Chen Dong-Liang;Hu Yu-Hai;Chen Yi;Zhang Xin-Yi;Wei Shi-Qiang   

  1. National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029;
  • Received:2002-09-24 Revised:2003-01-02 Published:2003-06-15
  • Contact: Wei Shi-Qiang

Abstract: The local structures of monolayer dispersive CuO/γ-Al2O3 catalysts prepared by means of impregnation have been investigated by XAFS technique.For the CuO/γ-Al2O3 sample with CuO loading 0.4 mmol/100 m2 lower than the monolayer dispersion threshold,the XAFS results indicate that only the first coordination shell appears in the radial distribution function of Cu atoms,and that the RCu-O and coordination number in the first shell are 0.195 nm and 4,respectively.Hence,we consider that the CuO active species on the surface of γ-Al2O3 are in the form of isolated atomic cluster ().Small amount of CuO nano-grains is formed onto the surface of γ-Al2O3 while the CuO loading is just equal to the threshold 0.8 mmol/100 m2.For sample with CuO loading of 1.2 mmol/100 m2,the local structure of Cu atom in CuO/γ-Al2O3 is similar to that of CuO powder.On the basis of the XAFS results,a monolayer dispersion model of CuO/γ-Al2O3 catalysts has been proposed.

Key words: Monolayer dispersion, CuO, XAFS(X-ray adsorption fine structure)