晶化时间对Hβ分子筛结构及噻吩烷基化反应的影响
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摘要
以四乙基氢氧化铵为模板剂,偏铝酸钠为铝源,氢氧化钠为钠源,硅胶为硅源,在不同晶化时间下水热合成了Hβ分子筛。采用X射线衍射(XRD)仪、扫描电子显微镜(SEM)、N2吸附-脱附(BET)法、氨程序升温脱附法对Hβ分子筛结构性质进行了表征。考察了晶化时间对分子筛结构和对噻吩烷基化性能的影响。表征结果表明:当晶化时间为120 h时,有利于Hβ分子筛的合成,合成的Hβ分子筛形貌规则且均匀、表面呈略粗糙的截顶八面体颗粒状,表面积和孔体积较大,酸性适中,且没有产生丝光沸石杂晶,纯度最佳。噻吩烷基化反应结果表明:晶化120 h得到的分子筛具有较高的噻吩转化率(93.2%),此时该催化剂上1-己烯对噻吩的选择性为76.7%。
The molecular sieve was synthesized at different crystallization time with TEAOH as template,NaAlO_2 as aluminum source,Na OH as sodium source,and silica gel as silicon source. The structural properties of molecular sieve Hβ were characterized by X-ray diffraction( XRD),scanning electron microscope( SEM),N_2 adsorption-desorption method( BET),and ammonia temperature programmed desorption. The effects of crystallization time on molecular sieve structure and performance of thiophene alkylation examines were investigated. The characterization results showed that the crystallization time( 120 h) contributed to compound the Hβ zeolite. The compounded Hβ zeolite had regular and uniform morphology,slightly rough truncated octahedral granulate surface with larger specific surface area and pore volume, moderate acidity,optimum purity and without mordenite mottle. The thiophene alkylation reaction results showed that the molecular sieve with crystallization time for120 h had the higher thiophene conversion( 93. 2%),and the 1-hexene on thiophene selectivity of catalyst was 76. 7%.
The molecular sieve was synthesized at different crystallization time with TEAOH as template,NaAlO_2 as aluminum source,Na OH as sodium source,and silica gel as silicon source. The structural properties of molecular sieve Hβ were characterized by X-ray diffraction( XRD),scanning electron microscope( SEM),N_2 adsorption-desorption method( BET),and ammonia temperature programmed desorption. The effects of crystallization time on molecular sieve structure and performance of thiophene alkylation examines were investigated. The characterization results showed that the crystallization time( 120 h) contributed to compound the Hβ zeolite. The compounded Hβ zeolite had regular and uniform morphology,slightly rough truncated octahedral granulate surface with larger specific surface area and pore volume, moderate acidity,optimum purity and without mordenite mottle. The thiophene alkylation reaction results showed that the molecular sieve with crystallization time for120 h had the higher thiophene conversion( 93. 2%),and the 1-hexene on thiophene selectivity of catalyst was 76. 7%.
引文
[1]Angvine P J,Mitchel K M,Oleck S M,et al.Hydrocracking progress use in zeolite Beta:US,4612108[P].1986-09-16.
[2]Kennedy C R.Catalytic cracking of paraffinic feedstocks with zeolite Beta:EP,0186447[P].1984-12-27.
[3]Chu P,Yen J H.Catalyst composition dewaxing of lubrication oils:US,4601993[P].1986-07-22.
[4]Bellussi G,Pazzuconi G,Perego C,et al.Liquid phase alkylation of benzene with light olefins catalyzed by Betz-zeolites[J].Journal of Ctalysis,1995,157(1):227-234.
[5]王立峰.微孔分子筛材料的合成及新合成体系的开拓[D].吉林:吉林大学,2008.
[6]李红权,崔冬芳.水热晶化法合成Beta沸石研究[J].工业催化,2006,14(z 1):449-451.
[7]魏书梅,徐亚荣,徐新良,等.HY分子筛催化噻吩类硫化物的烷基化反应动力学[J].化学反应工程与工艺,2012,28(2):159-163.
[2]Kennedy C R.Catalytic cracking of paraffinic feedstocks with zeolite Beta:EP,0186447[P].1984-12-27.
[3]Chu P,Yen J H.Catalyst composition dewaxing of lubrication oils:US,4601993[P].1986-07-22.
[4]Bellussi G,Pazzuconi G,Perego C,et al.Liquid phase alkylation of benzene with light olefins catalyzed by Betz-zeolites[J].Journal of Ctalysis,1995,157(1):227-234.
[5]王立峰.微孔分子筛材料的合成及新合成体系的开拓[D].吉林:吉林大学,2008.
[6]李红权,崔冬芳.水热晶化法合成Beta沸石研究[J].工业催化,2006,14(z 1):449-451.
[7]魏书梅,徐亚荣,徐新良,等.HY分子筛催化噻吩类硫化物的烷基化反应动力学[J].化学反应工程与工艺,2012,28(2):159-163.