磷改性β分子筛的制备及其在苯与乙烯烷基化反应中的应用

通过采用高温带压磷酸二氢铵溶液对β分子筛进行磷改性得到改性β分子筛催化剂，考察其在苯与乙烯高空速烷基化反应中的催化活性，并对其结晶度、元素组成、酸量、酸类型及骨架结构等物化性质进行表征。结果表明：经磷改性后，β分子筛催化剂的总酸量和B酸、L酸中心浓度均有明显提高，且磷元素的引入使改性β分子筛催化剂在31P MASNMR和27Al MASNMR表征谱图中，在化学位移为－30.908和41.392处均有一强吸收峰，证明β分子筛的骨架结构中有P（4Al）和Al（4P）四配位结构出现，稳定了骨架铝，提高了催化剂的活性稳定性。当P2O5在催化剂中的质量分数为2%时，该催化剂在苯与乙烯高空速烷基化反应中的活性稳定性最佳。

PREPARATION OF PHOSPHORUS MODIFIED ZEOLITE BETA AND ITS APPLICATION IN BENZENE-ETHYLENE ALKYLATION REACTION

Phosphorus modified β zeolite samples were prepared by using ammonium biphosphate solution under high temperature and pressure.The crystallinity,elemental composition,acidity and structure of the phosphorus modified β zeolite samples were characterized,and their catalytic activities during benzene-ethylene alkylation under high space velocities were investigated.Results showed that the total acid amount,B-acid sites and L-acid sites of the P-modified β zeolite samples increased significantly.Furthermore,structures of P(4Al) and Al(4P) were found existing in the framework of P-modified β zeolite as shown by 31 P MASNMR and 27 Al MASNMR spectra,thus the framework aluminum atoms were stabilized and the activity stability of the zeolite catalyst enhanced.P-modified β zeolite catalyst with 2% P2O5 exhibited the best activity stability during benzene-ethylene alkylation under high space velocity.