MgO/HMCM-22择形催化乙苯与碳酸二乙酯烷基化合成对二乙苯  

Selective Synthesis of Para-diethylbenzene by the Alkylation of Ethylbenzene with Diethyl Carbonate over MgO modified HMCM-22 Catalysts

作　　者：于楼云[1] 薛冰[1] 许杰[1] 李永昕[1] 

机构地区：[1]常州大学石油化工学院,江苏常州213164

出　　处：《分子催化》2011年第1期59-63,共5页Journal of Molecular Catalysis(China)

基　　金：江苏省高技术研究项目(BG2006015)

摘　　要：以硝酸镁为前驱体,通过等体积浸渍法制备不同负载量的MgO/HMCM-22催化剂.用X射线衍射、NH3程序升温脱附和吡啶吸附红外光谱表征催化剂的结构和酸性.在气相连续流动固定床反应器上考察了MgO负载量、反应温度、乙苯(EB)与碳酸二乙酯(DEC)摩尔比对EB与DEC烷基化反应合成对二乙苯(p-DEB)的影响.实验结果表明:B酸中心是EB与DEC烷基化反应的活性中心.随着MgO负载量的增加,EB转化率降低,而p-DEB选择性明显提高.采用12%MgO/HMCM-22为催化剂,在反应温度为360℃、n(EB)/n(DEC)=1∶2,p-DEB选择性高达64.4%.A series of MgO/HMCM-22 catalysts prepared by wet impregnation method have been tested for the synthesis of p-diethylbenzene（p-DEB） by the alkylation of ethylbenzene（EB） with diethyl carbonate（DEC） using a fix-bed reactor.Several techniques such as X-ray diffraction,NH3-TPD,and pyridine-IR were applied to characterize the structure and acidic properties of the as-synthesized catalysts.By analysis of results of the characterization,the alkylation of EB with DEC occurred mainly on Brnsted acid sites.Furthermore,the effects of MgO loading amount,reaction temperature,and the ratio of EB to DEC on the catalytic performance have been investigated.Catalytic tests demonstrated that,with the increase of the loading amount MgO,the conversion of EB decreased while the selectivity to p-DEB increased dramatically.The best catalytic performance was obtained over the 12%MgO/HMCM-22 catalyst under 360 ℃ with a ratio of EB to DEC of 1∶2,affording a remarkable p-DEB selectivity（64.4%）.

关 键 词：MCM-22分子筛 氧化镁 乙苯 碳酸二乙酯 对二乙苯 

分 类 号：O643.32[理学—物理化学]