SCM-36分子筛纳米片用于乙烯和2,5-二甲基呋喃转化制可再生对二甲苯  

SCM‐36 zeolite nanosheets applied in the production of renewable p‐xylene from ethylene and 2,5‐dimethylfuran

作　　者：马多征 李相呈 刘闯 Caroline Versluis 叶迎春 王振东 Eelco T.C.Vogt Bert M.Weckhuysen 杨为民[1,2] Duozheng Ma;Xiangcheng Li;Chuang Liu;Caroline Versluis;Yingchun Ye;Zhendong Wang;Eelco T.C.Vogt;Bert M.Weckhuysen;Weimin Yang(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;State Key Laboratory of Green Chemical Engineering and Industrial Catalysis,Sinopec Shanghai Research Institute of Petrochemical Technology,Shanghai 201208,China;Inorganic Chemistry and Catalysis group,Institute for Sustainable and Circular Chemistry and Debye Institute for Nanomaterials Science,Utrecht University,Universiteitsweg 99,3584 CG Utrecht,the Netherlands)

机构地区：[1]华东理工大学化工学院,上海200237 [2]中国石化上海石油化工研究院,绿色化工与工业催化国家重点实验室,上海201208 [3]乌得勒支大学德拜纳米材料科学研究所,可持续与循环化学研究所,无机化学与催化组,荷兰乌得勒支

出　　处：《Chinese Journal of Catalysis》2023年第4期200-213,共14页催化学报（英文）

基　　金：国家自然科学基金(21972168,21802168);国家留学基金委(CSC);中国石油化工股份有限公司.

摘　　要：分子筛是一类重要的结晶多孔材料,广泛应用于化学工业.开发新型分子筛特别是硅铝酸盐分子筛,一直是该领域的研究热点.分子筛的晶化过程一般需要结构导向剂的参与,包括碱(土)金属离子为代表的无机阳离子,有机胺或季铵盐为代表的有机物以及分子筛晶种.采用两种及以上结构导向剂的分子筛合成策略,具有调节分子筛骨架原子、晶体形貌和化学组成的作用,是开发新分子筛的有效手段.对二甲苯(PX)是合成对苯二甲酸乙二醇酯(PET)的重要原料.PX主要来源于石油资源,开发基于生物质原料生产PX的技术有利于缓解日益严峻的环境和能源危机.本文采用两种有机结构导向剂,以四甲基氢氧化铵(TMAOH)为有机结构导向剂,同时向体系中加入十六烷基溴化吡啶(C_(16)Py Br)或正辛基三甲基氯化铵(OTMAC),合成了一种新型铝硅酸盐分子筛,命名为SCM-36(Sinopec Composite Material No.36).SCM-36分子筛具有独特的X射线粉末衍射谱图(XRD)和纳米片状形貌.原位XRD结果表明,SCM-36分子筛在焙烧过程中由于晶胞收缩而导致衍射峰的偏移.扫描电子显微镜(SEM)、原子力显微镜以及共聚焦荧光成像显微镜表征结果表明,分子筛为纳米片形貌,厚度为6.9-14.9 nm.N_(2)和Ar物理吸附-脱附结果表明,SCM-36分子筛的BET表面积为355 m^(2)/g,其具有0.59 nm和0.67 nm左右孔尺寸的微孔孔道.两种有机结构导向剂都进入了分子筛孔道,在焙烧时于不同的温度区间发生分解.原位CO傅里叶变换红外光谱结果表明,SCM-36的Brönsted酸强度(△υ(CO…OH)=313 cm^(-1))与ZSM-5相当.采用原位紫外可见光吸收光谱监测4-甲氧基苯乙烯和4-氟苯乙烯的低聚探针反应过程,证实了SCM-36分子筛同时具有强酸和弱酸,且以弱酸为主的酸性质.在催化DMF和乙烯制备PX的反应中,SCM-36分子筛不仅表现出与传统分子筛(ZSM-5,Beta)相当的高转化率,而且表现出更高的PX选择�Zeolites as solid acid materials have played important roles in industrial catalysis.The attempts to obtain new zeolite framework structures and related chemical compositions have never stopped,and may expand the application thereof.Using renewable bioderived molecules as starting feedstocks would be of great help in building a more circular carbon cycle.However,zeolites have only shown limited efficiency in the conversion or production of bioderived chemicals.In this work,we report on the synthesis of a new aluminosilicate zeolite named SCM‐36(Sinopec Composite Material No.36)using tetramethylammonium hydroxide(TMAOH)with the presence of hexadecylpyridinium bromide hydrate(C_(16)PyBr)or octyltrimethylammonium chloride(OTMAC).The pore opening of this new zeolite material is about 0.6 nm,which is consistent with the size of 10 to 12 membered ring channel.SCM‐36 possesses a nanoflower‐like morphology with a thickness of~20 nm.The SiO_(2)/Al_(2)O_(3)molar ratio of the SCM‐36 material is ranging from 21.2 to 36.6,with most Al incorporated into the zeolite framework structure.The acid strength of SCM‐36 is not strong,as confirmed by various techniques,including NH_(3)‐TPD,pyridine FT‐IR,ex‐situ confocal fluorescence microscopy and in‐situ UV‐Vis micro‐spectroscopy.In the catalytic conversion of bio‐derived 2,5‐dimethylfuran(DMF)and ethylene into para‐xylene(PX),H‐SCM‐36 zeolite showed better performance than the more traditional zeolites.The highest selectivity towards PX reached a value of~93%.Besides,SCM‐36 zeolite showed remarkable recyclability in the reaction.

关 键 词：分子筛 硅铝酸盐 SCM-36 原位光谱 对二甲苯 生物质 

分 类 号：O625.11[理学—有机化学] O643.36[理学—化学] TB383.1[一般工业技术—材料科学与工程]