Thermal Removal of Ammonia from Mordenite

Two types of NH+4 cations can be distinguished in the surface layer of NH+4 mordenite by XPS, viz., NH+4 cations coordinated in the side pockets (22%) and in the main channels (78%). Additionally, nonframework SiOx species were observed in the mordenite. Thermal activation of NH+4 mordenite at 400°C causes the appearance of two types of atomic nitrogen strongly chemisorbed on these SiOx nonframework species.