Fourier-transform infrared studies of copper-containing Y zeolites. Dehydration, reduction and the adsorption of ammonia

Abstract

The reduction of CuII to CuI ions in partially CuII-exchanged zeolite Y by CO plus co-adsorbed NH3 has been studied (298–673 K) using Fouriertransform infrared spectroscopy. While the data are complex the formation of a variety of species including [Cu(NH3)]2+, [CuCO(NH3)n]+, NH+4 and hydrogen-bonded NH3 have been identified. The data indicate that at low temperature reduction by NH3 is dominant while at elevated temperature CO is a more important reducing agent.