分子筛催化甲苯酰化反应研究

Study of acylation of toluene over molecular sieves catalysts

在对传统酰基化反应的催化剂改进中,HZ-1沸石分子筛显示了很好的催化性能.以甲苯为底物,分别以苯甲酰氯和苯酐为酰化剂,考察了在不同酰化剂下催化剂的催化性能,发现苯甲酰氯在此催化剂催化下显示了较高的反应活性和选择性.苯甲酰氯为酰化剂的最佳优化条件:甲苯和苯甲酰氯物质的量比为2.5∶1,四次交换的HZ-1沸石用量2g,反应温度130℃,反应时间15h,4-甲基二苯甲酮色谱收率可达94.8%;苯酐为酰化剂时,催化剂采用用量为2.5g的二次交换的HZ-1沸石,物料配比为4∶1,反应温度250℃,反应时间为5h,目标产物2-甲基蒽醌的色谱收率为65.09%,苯酐转化率为71.3%.两种酰化剂都具有很好的工业化前景.

HZ-1 zeolite molecular sieves were found high catalytic performance in the process of improving the traditional acylating catalysts. Using toluene as substrate,the catalytic performance of zeolite molecular sieves was investigated with different acylating agent benzoyl chloride and phthalic anhydride,respectively. It is concluded that benzoyl chloride exhibits higher activity and selectivity compared with phthalic anhydride in the reaction. When toluene and benzoyl chloride react for 15 h at 403 K with the ratio of 2.5：1 and the used quantity of four times ion-exchanged HZ-1 zeolite is 2 g,the chromatographic yield of 4-methyl benzophenone can reach 94.8%. As for the phthalic anhydride,the conversion of phthalic anhydride and the chromatographic yield of 2-methyl anthraquinone can reach 71.3% and 65.09%,respectively. The optimal quantity of two times ion-exchanged HZ-1 zeolite is 2.5 g,and the optimal ratio of toluene to phthalic anhydride is 4：1 when the reaction time and temperature are 5 h and 523 K respectively. Both of them have excellent industrial prospects.