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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。
USY molecular sieve was used to catalyze the alkylation of toluene and tert-butanol with phosphoric acid. The catalysts were characterized by XRD, BET, NH3-TPD and TG-DTA. The experimental results show that the ammoniation and acid modification did not change its crystal structure, but the number of micropores decreased, the specific surface area increased slightly, and the amount of catalyst acid increased. USY catalyzed by 0.005 mol / L phosphoric acid showed the best catalytic performance with the conversion of toluene up to 25% and the selectivity of PTBT up to 62%. The clogging of micro-pores formed by carbon and oligomer is the main reason for the catalyst deactivation. The catalyst basically achieves the activity of fresh catalyst after calcination at 550 ℃.