作 者: ;
机构地区: 广州大学生物与化学工程学院
出 处: 《广州大学学报(自然科学版)》 2004年第1期20-23,共4页
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 Brnsted and Lewis acidic centers. Brnsted acidic centers are stronger and the main source of the acidity of molecular sieve. However, Lewis acidic centers are weaker than Brnsted ones.