Abstract:

The solid-state interaction between CuCl and NH4Y has been followed in situ by infrared and mass spectroscopy. Upon heat-treatment of the mixture of CuCl / NH4Y, the protons in the β cages and supercages of the zeolites can be equally replaced by Cu(Ⅰ) cations of CuCl. The degree of the exchange increases with increasing the reaction temperatures, but levels off at a temperature higher than 420 ℃. Compare the infrared results of CO adsorption on Cu(Ⅰ) of Cu(Ⅰ)Y prepared by solid-state reaction with those on Cu(Ⅰ) of Cu(Ⅱ)Y obtained by auto-reduction at a high temperature in vacuo, the characteristics of Cu(Ⅰ) species in both of the zeolites are similar. Based on the EPR results of Cu(Ⅱ)Y reduced in CO at different temperatures, one could conclude that the solid-state ion exchange between CuCl and NH4Y is an effective method for the preparation of Cu(Ⅰ)Y zeolites.

Key words: Solid-state ion exchange, Cu(I)Y zeolites, IR, MS, EPR