MgO改性无粘结剂ZSM-5分子筛制备及催化苯与乙烯烷基化反应性能  

MgO Modified Binder-free ZSM-5 Catalyst and Its Catalytic Performance for Benzene Alkylation with Ethylene

作　　者：马翀玮 沈震浩[2,3] 蔡焕焕 王达锐 孙洪敏 杨为民[1,2] 朱志荣[3] MA Chongwei;SHEN Zhenhao;CAI Huanhuan;WANG Darui;SUN Hongmin;YANG Weimin;ZHU Zhirong(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;State Key Laboratory of Green Chemical Engineering and Industrial Catalysis,Shanghai Research Institute of Petrochemical Technology,SINOPEC,Shanghai 201208,China;College of Chemical Science and Engineering,Tongji University,Shanghai 200092,China)

机构地区：[1]华东理工大学化工学院,上海200237 [2]绿色化工与工业催化国家重点实验室,中国石油化工股份有限公司上海石油化工研究院,上海201208 [3]同济大学,化学科学与工程学院,上海200092

出　　处：《化学反应工程与工艺》2020年第4期289-296,共8页Chemical Reaction Engineering and Technology

基　　金：国家重点研发计划(2017YFB0702800)。

摘　　要：通过气固相晶化法使成型ZSM-5催化剂中粘接剂结晶转化,合成了无粘结剂ZSM-5分子筛催化剂条形颗粒,并采用浸渍法对其进行了MgO改性及制备。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、氮气物理吸附、NH3程序升温脱附(NH3-TPD)等手段表征了催化剂物化性质和酸性质。考察了其在苯和乙烯烷基化反应中的择形催化性能,并进行了合成乙苯联产对二乙苯的探索实验,研究了催化剂中粘结剂和MgO对反应活性、择形选择性、稳定性等性能的影响。结果表明:MgO改性不仅钝化了ZSM-5分子筛外表面酸性,还能进入孔道使分子筛酸量减少,使得整体酸强度减弱。相较于含粘结剂的分子筛催化剂,MgO改性后的无粘结剂ZSM-5分子筛催化剂具有更好的改性择形催化性能,表现出优异的反应活性、对二乙苯择形选择性。而且因为无粘结剂ZSM-5分子筛具有丰富的微-介孔复合结构与合适的酸性,该催化材料具有较好的反应稳定性。The typed binder-free ZSM-5 catalyst synthesized by the gas-phase re-crystallization method was modified by MgO via impregnation.Its physicochemical properties,as well as acidic properties,were characterized by X-ray diffraction(XRD),scanning electron microscope(SEM),N2 adsorption,NH3 temperature programmed desorption(NH3-TPD),etc.Their catalytic performances were tested by benzene alkylation with ethylene to ethylbenzene(EB),in which para-diethylbenzene(p-DEB)was produced as another main product.The effects of silica-binder and MgO on the reactivity,shape selectivity and stability were investigated.It was found that MgO might not only passivate the acid sites on ZSM-5’s external surface but also enter the internal pore system.As a result,the amount and strength of the acid sites were reduced.Because these modification effects were even better when binder-free ZSM-5 was used as the substrate,the MgO modified binder-free ZSM-5 showed higher reactivity and para-DEB shape selectivity in benzene alkylation with ethylene than the MgO modified ZSM-5 containing a silica binder.Moreover,the MgO modified binder-free ZSM-5 was much more stable due to its feature with its abundant micropores-mesopores and proper acidity.

关 键 词：对二乙苯 择形烷基化 无粘结剂ZSM-5 分子筛 氧化镁改性 

分 类 号：O643.32[理学—物理化学]