摘要
本文考察了在含稀土与不含稀土的ZSM-5沸石催化剂上,用甲苯、甲醇合成对二甲苯的反应性能.含稀土催化剂具有良好的综合反应性能,其甲苯转化率为20.7%,对二甲苯选择性为98.7%,经50h 连续运转仍未失活。从红外光谱法和氨吸附的程序升温脱附法测定的酸性质数据分析,减少催化剂表面上的L 酸中心,降低酸强度,保留适宜强度的B 酸中心是提高活性稳定性的必要条件.
The selective formation of p-xylene by alkylation of toluene with metha-nol over HZSM-5 type zeolite and ZSM-5 zeolites modified by mixed rareearth compounds were studied.Passing the mixture of toluene and methanol(1:1 mol ratio)over RE-containing catalyst in the presence of N_2/H_2,atspace velocity (toluene) of 5.5h^(-1) and 460℃ for 50 h gave a 20.7% tolueneconversion and a 98.7% p-xylene selectivity.Study of the surface acidity ofthese catalysts by IR and TPD showed that decteasing the number and thestrength of Lewis acid sites and retaining certain strength of Br(?)nsted acidsites are necessary for the enhancement of the stability of catalysts.
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
1989年第2期11-17,共7页
Acta Petrolei Sinica(Petroleum Processing Section)
