AN EXAFS STUDY ON CUCL NAY AND CUCL/GAMMA-AL2O3 SYSTEMS/

XAFS evidence shows that the dispersed Cu+ ions of CuCl/gamma-Al2O3 or CuCl/NaY have changed their coordination structure. Below the maxima of dispersion amounts (thresholds) with increase of contents, O neighb ors of Cu decrease and Cl neighbor; increase. When the loadings get to the thresholds, the coordination numbers of Cu-O and Cu-CI of the dis persed phase keep constant values. The results combing the adsorption behavior of systems indicate that although when CuCl disperses on gamm a-Al2O3 or NaY, Cu tends to coordinate with O on the surface of the su pport first, and the coordination mode has been changed, it has no inf luence to the adsorption ability and the key to improving the adsorpti on behavior is to increase the surface area and the dispersion amount.