无钠多级孔Beta分子筛的制备及其在乙醇脱水制乙烯反应中的催化性能研究  

Preparation of sodium-free hierarchical Beta zeolites and their catalytic performance research in ethanol dehydration to ethylene

作　　者：王诗瑶 段慧娟 陈益胜 WANG Shiyao;DUAN Huijuan;CHEN Yisheng(College of Food Science and Engineering,Shanxi Agricultural University,Jinzhong 030801,Shanxi,China)

机构地区：[1]山西农业大学食品科学与工程学院,山西晋中030801

出　　处：《天然气化工—C1化学与化工》2022年第6期77-82,共6页Natural Gas Chemical Industry

基　　金：山西农业大学科技创新基金(2020BQ09,2020BQ49);山西省高等学校科技创新项目(2020L0145,2020L0171);山西省优秀博士来晋工作奖励资金科研项目(SXYBKY2019010,SXYBKY2019009)。

摘　　要：以自合成的双子季铵碱[C_(12)H_(25)(CH_(3))_(2)N^(+)(CH_(2))_(6)N^(+)(CH_(3))_(2)C_(12)H_(25)][OH^(-)]_(2)为介孔模板剂和碱源,采用一步水热法制备了孔道结构丰富多变的无钠多级孔Beta分子筛。采用X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、N_(2)吸/脱附和NH_(3)程序升温脱附(NH_(3)-TPD)分析了该分子筛的物理化学性质,并评价了其在乙醇脱水制乙烯反应中的催化性能。结果表明,与全微孔Beta分子筛相比,无钠多级孔Beta分子筛具有类蠕虫状的介孔孔道结构,其比表面积可达622.0 m^(2)/g,介孔孔体积占比可达0.853,且介孔平均孔径为9.551 nm。无钠多级孔Beta分子筛具有更好的催化性能,乙醇转化率可达96%,乙烯选择性可达89%。丰富的孔道结构有利于提高该分子筛的催化活性和稳定性。The hierarchical sodium-free Beta zeolite with rich and variable pore structure was prepared by one-step hydrothermal method using the self-synthesized binary quaternary ammonium alkali[C_(12)H_(25)(CH_(3))_(2)N^(+)(CH_(2))_(6)N^(+)(CH_(3))_(2)C_(12)H_(25)][OH^(-)]_(2) as the mesoporous template and alkali source.The physical and chemical properties of the zeolite were analyzed by X-ray diffraction(XRD),scanning electron microscope(SEM),transmission electron microscope(TEM),N_(2) absorption/desorption and NH_(3) temperature programmed desorption(NH_(3)-TPD),and its catalytic performance in the reaction of ethanol dehydration to ethylene was evaluated.The results show that,compared with the all-microporous Beta zeolite,the hierarchical sodium-free Beta zeolite has worm-like pore structure.Its specific surface area can reach 622.0 m^(2)/g,pore volume ratio can reach 0.853,and average pore diameter is 9.551 nm.The hierarchical sodium-free Beta zeolite has better catalytic properties.Its ethanol conversion rate can reach 96% and ethylene selectivity rate can reach 89%.The rich pore structure is beneficial to improve the catalytic activity and stability of this zeolite.

关 键 词：乙醇 乙烯 Beta分子筛 双子季铵碱 催化性能 

分 类 号：TS205.9[轻工技术与工程—食品科学]