果糖酸处理HZSM-5己烯芳构化催化剂的结构及性能

Structure and performance of HZSM-5 hexene aromatization catalyst treated with fructose acid

为提高HZSM-5己烯芳构化催化剂的BTX(苯、甲苯、二甲苯)选择性和寿命,利用果糖酸对HZSM-5进行处理(F-HZS),并与磷酸和硝酸处理的HZSM-5(P-HZS和N-HZS)进行对比,采用XRD、XRF、N_(2)吸附-脱附、NH_(3)-TPD、Py-FTIR等方法对催化剂结构进行表征,考察了催化剂己烯芳构化的催化性能。实验结果表明,酸处理后催化剂的MFI结构保留完整,且出现了介孔结构。催化剂的孔体积、硅铝比及B酸量和L酸量比值(B/L)增加,但酸量及酸强度下降,F-HZS的B/L最高,BTX选择性和寿命也明显高于P-HZS和N-HZS。在0.2 MPa、405℃,质量空速2 h-1条件下,F-HZS的BTX选择性为61.34%,寿命为60 h。

To improve BTX(benzene,toluene,xylene)selectivity and the lifetime of HZSM-5 as the hexene aromatizion catalyst,HZSM-5 was treated with fructose acid(F-HZS)compared with HZSM-5 treated with phosphoric acid and nitric acid(P-HZS and N-HZS).The structure of the catalyst was characterized by XRD,XRF,N_(2)adsorption-desorption,NH_(3)-TPD,and Py-FTIR,and its catalytic performance in hexene aromatization was also investigated.The results show that the MFI structure of the catalyst remains intact and mesoporous structure appears after acid treatment.The pore volume,silicon aluminum ratio,and the ratio of B acid amount to L acid amount(B/L ratio)of the catalyst increase,while the acid amount and strength decrease.F-HZS exhibits the highest B/L ratio,with significantly higher BTX selectivity and lifetime compared to P-HZS and N-HZS.At 0.2 MPa,405℃,and WHSV=2 h-1,F-HZS demonstrates BTX selectivity of 61.34%and lifetime of 60 h.