龙奕华,刘闯,武晓珂,杨艳伟,王正宝

• 1:浙江省化工高效制造技术重点实验室浙江大学化学工程与生物工程学院

摘要(Abstract)：

以ZSM-5晶体为核，将二氧化硅(SiO2)、四丙基溴化铵(TPABr)和氟化铵(NH4F)固体研磨成粉作为原料，采用固相合成法制备ZSM-5@silicalite-1核壳分子筛催化剂；并借助X射线衍射仪(XRD)、扫描电镜(SEM)、X射线能谱仪(EDS)、透射电子显微镜(TEM)、X射线光电子能谱仪(XPS)和2,6-二叔丁基吡啶吸附红外光谱(DTBPy-IR)等手段，对核壳分子筛催化剂的结构进行表征，考察其对甲苯甲醇烷基化反应的催化性能。结果表明，通过固相合成法，ZSM-5核晶体外表面外延生长出了全硅MFI型分子筛(silicalite-1)壳层，且该核壳催化剂表现出较高的对二甲苯(PX)选择性。还考察了核晶体尺寸对核壳结构催化剂的影响。研究发现，随着核晶体尺寸的增大，核壳分子筛的甲苯转化率下降、PX选择性上升。作为对比，采用传统水热合成法(液相合成法)制备了核壳分子筛，考察了核晶体尺寸的影响。研究发现，随核晶体尺寸增大，水热合成法制备的核壳分子筛的甲苯转化率呈现先减后增的趋势，PX选择性则相反。由此得出，固相合成法对于较大核晶体的壳层生长具有更好的适用性，表现出广阔的应用前景。

关键词(KeyWords)： MFI型分子筛;核壳结构;甲苯甲醇烷基化;对二甲苯;固相合成法;核晶体尺寸

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(21676238)

作者(Author): 龙奕华,刘闯,武晓珂,杨艳伟,王正宝

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