金属氧化物助剂对Pt/HZSM-5乙苯脱乙基催化剂性能的影响

Effect of auxiliary metal oxide on properties of ethylbenzene deethylation catalyst

采用共浸渍的方法,向Pt/HZSM-5乙苯脱乙基催化剂中引入第二金属氧化物MeO对其进行修饰,在微型固定床反应器上考察MeO含量对催化剂性能的影响,并利用XRD、BET和NH_3-TPD对催化剂进行了表征。研究发现:金属氧化物MeO的添加并未影响ZSM-5分子筛结构,但随着MeO负载量的增加,催化剂的比表面积逐渐降低,弱酸酸量先增加后减少、强酸酸量则先减少后增加。w(MeO)为3%的催化剂催化性能最佳,其乙苯转化率为61.5%、二甲苯选择性为23.8%、二甲苯损失率为0.5%、苯的选择性为95.0%。

The second metal oxide MeO was introduced into Pt/HZSM-5 ethylbenzene deethylation catalyst by co-impregnation,and the effect of MeO content on the catalytic performance of the catalyst was investigated in a fixed-bed micro-reactor.XRD,BET and NH3-TPD were used to characterize the catalysts.The results show that the addition of MeO don5t affect the structure of ZSM-5 molecular sieve.With the increase of the loading of MeO,the specific surface area of the catalyst decreases gradually,the acidity of the weak acid first increases and then decreases,and the acidity of the strong acid is just the opposite.The catalyst with a MeO loading of 3%by mass exhibited the best catalytic performance,giving a ethylbenzene conversion of 61.5%,a xylene selectivity of 23.8%,a xylene loss of 0.5%,and a benzene selectivity of 95.0%.