Abstract:

Five CuCl2/NaY sytems prepared with different methods were studied by XRD. One system is prepared by giving heat treatment to the solid mixture of CuCl2 and NaY. The other four systems are all prepared by impregnation methods ,NaY impregnated in CuCl2 solution of absolute alcohol, 0.05 mol•L(- 1) H2SO4, de-ionized water and 0.1 mol•L-1 HCl respectively. The results show that under certain conditons,CuCl2 could spontaneously disperse onto the NaY surface. The maximum dispersion capacity (threshold) is much larger than the amount of Cu ions exchanged onto NaY surface by ion exchange methods. The thresholds are very different according to different preparation processes. They are subject to two factors: the water adsorbed on NaY surface and the prior adsorption of HCl on NaY surface. These two factors can markedly reduce the threshold of CuCl2 on the surface of NaY zeolite. Meanwhile, under certain conditions, the dispersion state of Cu ion NaY surface could be changed obviously. The higher the pH value of NaY zeolite surface and the calcination temperation, the more obvious the hydrolization of CuCl2.

Key words: Spontaneous monolayer dispersion, X-ray diffraction, NaY zeolite, Copric chloride