不同硅铝比的MCM-22分子筛的气相硅烷化处理

对不同硅铝比的MCM-22分子筛进行气相硅烷化处理,并采用X射线衍射、固体核磁、N2吸附-脱附和甲苯吸附等技术对样品进行了表征.结果显示,原料硅铝比为50~100的MCM-22分子筛均可以利用气相硅烷化,在不脱除骨架铝的基础上,将Si(OH)2柱撑结构引入其层间超笼系统,从而使层间距增大,孔体积增加;将密度泛函理论用于计算硅烷化前后的MCM-22分子筛的N2吸附等温线,成功得到十元环孔道和超笼体系的比表面积和孔体积,发现气相硅烷化使MCM-22分子筛超笼体系的比表面积和孔体积增大,而十元环孔道减小.另外,气相硅烷化可有效提高不同硅铝比MCM-22分子筛的甲苯平衡吸附量....

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Published in催化学报 Vol. 34; no. 3; pp. 612 - 619
Main Author 高宁宁 谢素娟 刘盛林 刘克峰 李秀杰 徐龙伢
Format Journal Article
LanguageChinese
Published 中国科学院大学,北京100049%中国科学院大连化学物理研究所,辽宁大连,116023 2013
中国科学院大连化学物理研究所,辽宁大连116023
Subjects
MCM-22分子筛
MWW结构
密度泛函理论
层间扩孔
硅烷化
层间扩孔
MWW结构
密度泛函理论
硅烷化
MCM-22分子筛
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ISSN0253-9837
1872-2067
DOI10.3724/SP.J.1088.2013.20932

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Summary:对不同硅铝比的MCM-22分子筛进行气相硅烷化处理,并采用X射线衍射、固体核磁、N2吸附-脱附和甲苯吸附等技术对样品进行了表征.结果显示,原料硅铝比为50~100的MCM-22分子筛均可以利用气相硅烷化,在不脱除骨架铝的基础上,将Si(OH)2柱撑结构引入其层间超笼系统,从而使层间距增大,孔体积增加;将密度泛函理论用于计算硅烷化前后的MCM-22分子筛的N2吸附等温线,成功得到十元环孔道和超笼体系的比表面积和孔体积,发现气相硅烷化使MCM-22分子筛超笼体系的比表面积和孔体积增大,而十元环孔道减小.另外,气相硅烷化可有效提高不同硅铝比MCM-22分子筛的甲苯平衡吸附量.
Bibliography:MWW structure;MCM-22 zeolite;silylation;interlayer expansion;density functional theory
GAO Ningning a,b ,XIE Sujuan a,* ,LIU Shenglin a ,LIU Kefeng a,b ,LI Xiujie a ,XU Longya a,# a Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China b University of Chinese Academy of Sciences,Beijing 100049,China
21-1195/O6
MCM-22 precursor with various SiO 2 /Al 2 O 3 molar ratios was treated by vapor-phase silylation.MCM-22 zeolite and its products of vapor-phase silylation were characterized by X-ray diffraction,solid state nuclear magnetic resonance,N 2 adsorption-desorption,and toluene adsorption techniques.The results showed that Si(OH) 2 pillaring structure was formed in the interlayer of MCM-22 with SiO 2 /Al 2 O 3 molar ratios of 50-100 without extraction of framework aluminum through vapor-phase silylation,resulting in the expansion of interlayer distance and the increase of micropore volume.The N 2 adsorption-desorption isotherms of MCM-22 zeolite before and after silylation
ISSN:0253-9837
1872-2067
DOI:10.3724/SP.J.1088.2013.20932