三元尖晶石与孪晶ZSM-5分子筛在苯与二氧化碳甲基化中的应用  

Application of ternary spinel and twined ZSM-5 zeolite in methylation of benzene with carbon dioxide

作　　者：杨帆 赵溢涛 朱学栋[2] 王达锐 YANG Fan;ZHAO Yitao;ZHU Xuedong;WANG Darui(State Key Laboratory of Green Chemical Engineering and Industrial Catalysis,SINOPEC Shanghai Research Institute of Petrochemical Technology Co.,Ltd.,Shanghai 201208,China;Engineering Research Center of Large-Scale Reactor Engineering and Technology,Ministry of Education,School of Chemical Enigineering,East China University of Science&Technology,Shanghai 200237,China)

机构地区：[1]中石化(上海)石油化工研究院有限公司,绿色化工与工业催化全国重点实验室,上海201208 [2]华东理工大学化工学院,教育部大型工业反应器工程中心,上海200237

出　　处：《化工进展》2025年第2期856-866,共11页Chemical Industry and Engineering Progress

摘　　要：将三元尖晶石型锌镓铝金属氧化物和孪晶ZSM-5分子筛制备成双功能催化剂用于苯与二氧化碳甲基化反应。结果表明,相对于二元锌铝或锌镓金属氧化物和常规形貌ZSM-5分子筛组成的双功能催化剂,三元锌镓铝尖晶石可提高催化剂的活性,孪晶分子筛可有效增加产物中对二甲苯的含量。结合各种表征发现,三元锌镓铝尖晶石所具有的更多氧空位强化了二氧化碳的吸附,能够产生更多的甲基化中间体;同时,孪晶分子筛较少的表面酸性位点和较低的(010)晶面暴露程度有效抑制了分子筛表面二甲苯的异构化反应并凸显了对二甲苯的扩散优势,使产物中对二甲苯含量超过了热力学平衡组成。优化后的催化剂在425℃、3MPa的反应条件下表现出高达39.2%的苯转化率和37.1%的二氧化碳转化率,产物中甲苯、二甲苯总选择性为91.2%,且对二甲苯在二甲苯中的比例高达55.6%,催化性能相比二元尖晶石和常规ZSM-5组成的双功能催化剂有显著提升。Ternary spinel-type ZnGaAl metal oxide and twinned ZSM-5 zeolite were integrated to prepare bifunctional catalyst which were then applied in the methylation of benzene with carbon dioxide.Experimental results revealed that the ternary spinel effectively promoted the activity and the twinned ZSM-5 increased the para-xylene content in the products,compared with the bifunctional catalyst made from the binary ZnAl or ZnGa spinel and conventional ZSM-5 counterparts.This phenomenon can be attributed to the higher concentration of oxygen vacancies provided by the ternary ZnGaAl spinel which enhanced the adsorption towards carbon dioxide and therefore generated more intermediates to react with benzene.Besides,the weak surface acidities as well as the low exposure degree of(010)surface of twinned ZSM-5 efficiently suppressed the isomerization of xylene on zeolite surface and magnified the diffusion advantages of para-xylene.The optimal bifunctional catalyst at 425℃and 3.0MPa exhibited a benzene conversion of 39.2%and a CO_(2)conversion of 37.1%,with a total toluene and xylene selectivity of 91.2%and 55.6%of all the xylene isomers being para-xylene,which is significantly better than the bifunctional catalyst composed of binary spinel and conventional ZSM-5 zeolite.

关 键 词：二氧化碳 氢 苯 分子筛 复合材料 催化 

分 类 号：O643.36[理学—物理化学]