菱钾沸石(OFF)的离子交换及对SO_2气体吸附性能研究

Ion-exchange of Offretites and Their Adsorption Performances to SO_2

采用水热合成法制备了菱钾沸石(OFF),通过离子交换得到了H-OFF,L i-OFF,N a-OFF,K-OFF和C s-OFF.用XRD,SEM,TG,DTA,固体1H NM R,FT IR和低温氮吸附等手段研究了离子交换性质,发现其晶体结构和晶貌在离子交换过程中基本不变,热力学性质随阳离子类型的改变而发生很大变化.样品的比表面积和孔体积随阳离子的增大而减小,B酸随阳离子半径的增大而减小,L酸反之.测定沸石样品对酸性气体SO2的吸附结果表明,L i-OFF在低分压下对SO2有很好的吸附性能.

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 SO_2 show that Li-OFF exhibits a remarkable adsorption capability at lower pressure.