二甲醚催化转化制甲苯的反应研究  

Catalytic conversion of dimethyl ether to toluene over the molecular sieves modified with tungsten oxide

作　　者：王博[1,2] 王辉[1] 刘广波[1] 李琢[1] 李学民[1,2] 吴晋沪[1] 

机构地区：[1]中国科学院青岛生物能源与过程研究所生物燃料重点实验室,山东青岛266101 [2]中国科学院大学,北京100049

出　　处：《燃料化学学报》2014年第8期987-993,共7页Journal of Fuel Chemistry and Technology

基　　金：中国科学院重大科研装备研制项目(2011022);中国科学院战略先导专项(XDA07070301);山东省"泰山学者"岗位项目(ts200824085)

摘　　要：在氧气气氛中,对氧化钨改性的不同分子筛催化剂上二甲醚(DME)转化反应进行了评价。结果表明,WO3/HZSM-5催化剂上DME可以高选择性转化为甲苯,对其反应工艺条件进行了优化,常压、290℃、DME/O2比为2∶1时,二甲醚几乎完全转化,转化率为98.97%,甲苯的选择性达到39.71%。对催化剂结构和酸性进行表征,结果表明,ZSM-5分子筛的孔道结构最有利于甲苯的生成,WO3的介入调整了HZSM-5分子筛表面的酸性活性位点分布,在氧气气氛中有效地抑制了副产物的生成,使产物中甲苯的选择性提高。The catalytic performance of various zeolites modified with tungsten oxide in the conversion of dimethyl ether （DME） to toluene in the presence of oxygen was investigated in a continuous flow fixed-bed reactor. The results indicated that WO3/HZSM-5 as a catalyst is highly selective in the conversion of DME to toluene; under the optimized conditions, i.e. atmospheric pressure, 290℃, and with a DME/O2 mol ratio of 2 ： 1, the conversion of DME is 98.97 %, with the selectivity of 39.71% to toluene. The characterization results about the catalyst structure and acidity illustrate that the porous structure of ZSM-5 is suitable for the formation of toluene from DME. The doping of WO3 adjusts the distribution of the surface acid sites and then inhibits the formation of side-products in the presence of oxygen, which is able to enhance the selectivity to toluene.

关 键 词：二甲醚 催化转化 甲苯 WO3/HZSM-5 

分 类 号：O643.32[理学—物理化学]