H-beta分子筛催化苯与甲醇烷基化反应性能

摘要

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.