原位红外光谱考察分子筛表面酸性质  

Investigation on surface acidity of molecular sieve by in situ DRIFTS

作　　者：张平[1] 

机构地区：[1]广州大学生物与化学工程学院,广东广州510405

出　　处：《广州大学学报（自然科学版）》2004年第1期20-23,共4页Journal of Guangzhou University:Natural Science Edition

基　　金：国家自然科学基金资助项目(20076017);广东省自然科学基金资助项目(000428)

摘　　要：原位漫反射红外光谱用于表征磷酸硅铝分子筛SAPO 34表面酸性质,结果表明,SAPO 34分子筛中的桥联羟基Si OH Al具有较强的热稳定性.结合NH3探针考察表明,SAPO 34分子筛具有B酸和L酸两种酸中心,其中B酸较强,是SAPO 34酸性的主要部分,而L酸中心较弱.In situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) was used to investigate the surface acidity of SAPO-34 molecular sieve. The results show that the bridged Si-OH-Al groups in SAPO-34 have higher heat stability (873K). This method coupled with NH_3 molecular probes indicates that SAPO-34 has both Brnsted and Lewis acidic centers. Brnsted acidic centers are stronger and the main source of the acidity of molecular sieve. However, Lewis acidic centers are weaker than Brnsted ones.

关 键 词：原位红外光谱 SAPO—34分子筛 羟基 酸性 

分 类 号：O657.33[理学—分析化学]