Abstract: 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 ¹H 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.

Key words: Offretite, Ion-exchange, XRD, Thermal analysis, Acidic properties, Adsorption of SO₂