磷酸铝基Zn/HZSM-11催化剂用于苯和二甲醚烷基化反应

Aluminophosphate Bound Zn/HZSM-11Catalyst for Benzene Alkylation With Dimethyl Ether

在Zn/HZSM-11中添加不同磷/铝摩尔比(n(P)/n(Al))的磷酸铝黏结剂制备了系列催化剂(ZnZPAlO-x),并对其进行X射线衍射、N2吸附-脱附、NH3-TPD和O2-TPO表征,同时用于催化苯和二甲醚烷基化反应。结果表明,ZnZPAlO-x催化剂的比表面积、总孔体积以及酸量均随其n(P)/n(Al)的增加而降低。与含氧化铝黏结剂的催化剂(ZnZAl)相比,ZnZPAlO-x催化剂的苯转化率和苯甲基化产物选择性更高;反应后两者的积炭类型相似,但后者的积炭量更低。ZnZAl和ZnZPAlO-0.8(n(P)/n(Al)=0.8)催化苯和二甲醚烷基化反应的苯转化率随反应温度变化呈现不同规律,尤其在450℃高温条件下存在明显差异。

A series of catalysts （ZnZPAlO-x） were prepared by using Zn/HZSM-11 and aluminophosphate （PAlO） binder with different n （P）/n （Al）.The prepared catalysts were characterized by means of X-ray powder diffraction,N2-adsorption-desorption,NH3-TPD and O2-TPO,respectively,and were used as catalysts in benzene alkylation with dimethyl ether.The BET surface areas,total volumes and acid amounts of the catalysts declined with the increase of n（P）/n（Al）.Compared to the ZnZAl catalyst with pure Al2O3 as binder,ZnZPAlO-x showed higher benzene conversion and selectivity to benzene methylation products,and the coke amount on ZnZPAlO-x was lower,though the coke types were similar on both ZnZAl and ZnZPAlO-x.In addition,benzene conversions over the ZnZAl and ZnZPAlO-0.8 （n（P）/n（Al） =0.8） catalysts presented different principles with reaction temperature,especially at high reaction temperature of 450℃,obvious difference of benzene conversion existed.