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.
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)
出处
《天然气化工—C1化学与化工》
CAS
北大核心
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)。
关键词
乙醇
乙烯
Beta分子筛
双子季铵碱
催化性能
ethanol
ethylene
Beta zeolite
gemini quaternary ammonium base
catalytic performance
