摘要
采用磷酸改性处理USY分子筛气相催化甲苯与叔丁醇烷基化反应。利用XRD、BET、NH_3-TPD、TG-DTA等方法表征了催化剂。实验结果表明,氨化及酸改性处理并未改变其晶体结构,但微孔数量降低,比表面积略有增加,催化剂酸量增加。0.005 mol/L磷酸改性处理的USY催化性能最佳,甲苯转化率最高达25%,PTBT选择性高达62%。碳和低聚物形成的微孔隙的堵塞是催化剂失活的主要原因,550℃焙烧后催化剂基本达到新鲜催化剂的活性。
Vapour phase alkylation of toluene with tert-butyl alcohol over phospharic acid modified USY zeolite was studied. The midified catalyst was characterized by XRD, BET, NH3-TPD, and TG-DTA. The results showed that after modification the structure of USY was kept, but the number ofmocropores reduced, specific surface area slightly increased, and the amount of acid sites increased. The USY zeolite modified by phospharic acid of 0.005 mol/L presented better catalytic performance, the toluene conversion was about 25% and the selectivity of PTBT was about 62%. The clogging of micropores by formed carbon or oligomer was the main reason for the deactivation of the catalyst. By calcination at 550 ℃, deactivated catalyst can nearly renew to its original catalytic performance.
出处
《辽宁化工》
CAS
2016年第12期1467-1470,共4页
Liaoning Chemical Industry
