The ir studies of the status of Cu+ ions in CuZSM-5 CuBeta and in CuMCM-41

Abstract

The electron donor properties of Cu + and the ability to activate adsorbed molecules by π-back donation of d electrons of Cu + to π * antibonding orbitals of a molecule increases in the order: CuMCM-41<CuZSM-5<CuBeta. It was evidenced by IR studies of CO, N 2 , and NO adsorption. TPD-IR experiments provided information on heterogeneity of Cu + sites in all the zeolites studied. The experiments on the reduction (in H 2 ) and oxidation (in air) evidenced that the ability of Cu + to reduction and oxidation depends on zeolite structure. The ability to reduction increased in the order: CuMCM-41<CuBeta<CuZSM-5, whereas the ability to oxidation increased in the opposite order.