【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.更多还原

【Abstract】 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 NH₃ 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.更多还原