镍改性HZSM-5催化乙醇脱水制备乙烯  

Catalytic dehydration of ethanol to ethylene over nickel modified HZSM-5 catalysts

作　　者：李凤义[1,2] 刘宗章[1,2] 沈德建 张敏华[1,2] 

机构地区：[1]天津大学石油化工技术开发中心 [2]天津大学绿色合成与转化教育部重点实验室,天津300072

出　　处：《现代化工》2013年第5期54-57,共4页Modern Chemical Industry

摘　　要：在前期研究工作的基础上,通过正交实验对离子交换法制备Ni-HZSM-5的离子交换液浓度、交换温度和交换次数3个因素进行了考察。结果表明:硝酸镍溶液浓度为0.4 mol/L,交换温度为80℃,交换次数为2次时,制备的Ni-HZSM-5催化乙醇脱水制乙烯的效果最好。其中硝酸镍浓度对乙醇转化率和乙烯选择性的影响都最大。选取了3个催化剂和未改性的HZSM-5分别进行了XRD、BET和Py-TPD表征。最后对最佳条件下制备的Ni-HZSM-5进行了稳定性测试,15 h内乙醇转化率和乙烯选择性保持大于95%,催化性能得到显著提高。Based on the previous work, three factors of the conditions of ion-exchange method to prepare Ni-HZSM- 5 are studied by orthogonal experimental design, including the concentration of the ion-exchange solution, the ion- exchange temperature and the ion-exchange times. The results of catalytic evaluation indicate that the catalysts prepared under the condition of 0.4 mol/L Ni （ NO3 ） 2,80℃ and two ion-exchange times, show the best performance on the reaction ethanol to ethylene. Among the three factors, the concentration of Ni（ NO3 ）2 has the most important effect on the ethanol conversion and ethylene selectivity. Three catalyst samples and the parent HZSM-5 are chosen to conduct a series of characterization,including XRD, BET and Py-TPD. The results reveal that the catalysts have different ratios of the amount of weak acid sites to strong acid sites. The more weak acid sites cause the better catalyst activity and ethylene selectivity. At last, Ni-HZSM-5 prepared under the optimal condition is evaluated. The result shows that ethanol conversion and ethylene selectivity are both improved markedly, keeping over 95% for 15 h.

关 键 词：乙醇 乙烯 离子交换 HZSM-5 

分 类 号：O643.32[理学—物理化学]