Ion-exchange of offretites and their adsorption performances to SO2

Offretite (OFF) was synthesized through hydrothermal method, and H-OFF, Li-OFF, Na-OFF, K-OFF, Cs-OFF were obtained by ion-exchange. Subsequently, the samples were characterized by using XRD, SEM, nitrogen sorption, TG/DTA, FT-IR and solid-state H-1 NMR. The structures and morphologies of the samples do not change during the ion-exchange. The thermodynamic properties, surface area, micropore volume and acidic properties change with variation of the cation types in the pores. The results of adsorption of the exchanged zeolites to SO2 show that Li-OFF exhibits a remarkable adsorption capability at lower pressure.