H-beta分子筛催化苯与甲醇烷基化反应性能

Catalytic performance of H-beta zeolites for alkylation of benzene and methanol

采用两种促进剂协同作用改性制得了H-beta分子筛催化剂,通过XRD、BET及Py-IR对催化剂结构、比表面积及酸性变化进行表征,并将催化剂用于苯与甲醇烷基化测试其催化性能。结果表明,在反应压力为常压、反应温度400℃、空速2 h-1和苯与甲醇物质的量比为1∶1的最优条件下,苯转化率达到42. 5%、甲苯选择性为74. 6%,甲苯和二甲苯总选择性达到了94. 5%。基于结构及性能的研究,探讨了催化烷基化反应机理。

H-beta zeolites catalyst was modified by synergistic effect of two accelerants.Meanwhile,structure,specific surface area and acid change of catalyst were characterized by XRD,BET and Py-IR.Catalyst was tested in alkylatipon of benzene and methanol.Results showed that under the optimum reaction pressure of atmospheric pressure,MHSV=2 h-1,reaction temperature of 400℃,molar ratio of benzene/methanol=1∶1,benzene conversion reached 42.5%,selectivity of toluene was 74.6%,total selectivity of toluene and xylene reached 94.5%.The mechanism of catalytic alkylation was discussed based on study of structure and performance.