阴离子改性MCM-22分子筛的制备及其在催化合成聚甲氧基二甲醚中的应用
|
摘要
以硅溶胶为硅源,偏铝酸钠为铝源、环己亚胺为模板剂,采用水热合成法和离子交换法合成了HMCM-22分子筛,通过在合成凝胶时引入不同的阴离子制备了改性分子筛HMCM-22(X),利用XRD、FTIR、SEM、N_2吸附-脱附、~(27)Al NMR和NH_3-TPD等方法分析了阴离子对Al在MCM-22结构中落位的影响,同时考察了HMCM-22(X)骨架中酸中心位置和酸性质对合成聚甲氧基二甲醚(PODE_n)的影响。实验结果表明,HMCM-22(X)的拓扑结构未发生改变。阴离子并未掺杂到MCM-22的晶体结构中,但对试样的比表面积影响较大。阴离子的存在使催化剂的酸性位点更多地分布在催化剂的外表面和超笼处。阴离子不同,外表面形成的酸量和酸强度不同。PODE_n的形成受酸性位点和酸性质的共同影响,外表面的中强酸更有利于增链反应进行,HMCM-22(NO_3~-)和HMCM-22(ClO_4~-)的催化效果好于HMCM-22(SO_4~(2-))。
HMCM-22 zeolites were prepared by a hydrothermal synthesis method and an ion exchange method using silica sol as silicon source,sodium aluminate as aluminum source and hexamethyleneimine as template.HMCM-22(X)zeolites were prepared by introducing different anions to the synthesis gel.XRD,FTIR,SEM,N_2 adsorption-desorption,~(27)Al NMR and NH_3-TPD were carried out to characterize the influence of anions on the location of Al in MCM-22.The effects of acid center positions and acidity on the synthesis of PODE_n were also investigated.The results showed that the topology structure of HMCM-22(X)was not changed.The anions were not doped in the crystal structure,but it had a large influence on the specific surface area,and allowed the acid sites of the catalyst to be distributed more at the outer surface of the catalyst and at the supercage.The influence on the amount of acid and acid strength was different by introducing different anions The synthesis of PODE_n was affected by the acid center positions and acid properties,and the mediate strong acid on the outer surface was more favorable for the chain extension.The catalytic performances of HMCM-22(NO_3~-)and HMCM-22(ClO_4~-)were better than that of HMCM-22(SO_4~(2-))
HMCM-22 zeolites were prepared by a hydrothermal synthesis method and an ion exchange method using silica sol as silicon source,sodium aluminate as aluminum source and hexamethyleneimine as template.HMCM-22(X)zeolites were prepared by introducing different anions to the synthesis gel.XRD,FTIR,SEM,N_2 adsorption-desorption,~(27)Al NMR and NH_3-TPD were carried out to characterize the influence of anions on the location of Al in MCM-22.The effects of acid center positions and acidity on the synthesis of PODE_n were also investigated.The results showed that the topology structure of HMCM-22(X)was not changed.The anions were not doped in the crystal structure,but it had a large influence on the specific surface area,and allowed the acid sites of the catalyst to be distributed more at the outer surface of the catalyst and at the supercage.The influence on the amount of acid and acid strength was different by introducing different anions The synthesis of PODE_n was affected by the acid center positions and acid properties,and the mediate strong acid on the outer surface was more favorable for the chain extension.The catalytic performances of HMCM-22(NO_3~-)and HMCM-22(ClO_4~-)were better than that of HMCM-22(SO_4~(2-))
引文
[1]史高峰,陈英赞,陈学福,等.聚甲氧基二甲醚研究进展[J].天然气化工,2012,37(2):74-78.
[2]刘康军,张朝峰,李瑞丰.聚甲氧基甲缩醛的最新研究进展[J].化工进展,2013,32(11):2593-2598.
[3]Baranowski C J,Bahmanpour A M,Kr?Cher O.Catalytic synthesis of polyoxymethylene dimethyl ethers(OME):A review[J].Appl Catal,B,2017:407-420.
[4]雷艳华,孙清,陈兆旭,等.合成聚甲醛二甲基醚反应热力学的理论计算[J].化学学报,2009,67(8):767-772.
[5]张向京,武朋涛,蒋子超,等.聚甲醛二甲醚反应热力学分析[J].化学工程,2015,43(4):39-44.
[6]Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences.Method for preparing polymethoxymethylal:US7560599[P].2009-07-14.
[7]Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences.Method for synthesizing polyoxymethylene dimethyl ethers by ionic liquid catalysis:US8344183[P].2013-01-01.
[8]Li Huaju,Song Huanling,Chen Liwei,et al.Designed SO42-/Fe2O3-SiO2 solid acids for polyoxymethylene dimethyl ethers synthesis:The acid sites control and reaction pathways[J].Appl Catal,B,2015,165:466-476.
[9]赵启,王辉,秦张峰,等.分子筛催化剂上甲醇与三聚甲醛缩合制聚甲醛二甲醚[J].燃料化学学报,2011,39(12):918-923.
[10]Bevilacqua M,Meloni D,Sini F,et al.A study of the nature,strength,and accessibility of acid sites of H-MCM-22 zeolite[J].J Phys Chem,C,2008,112(24):9023-9033.
[11]Zhou Danhong,Bao Ying,Yang Mingmei,et al.DFTstudies on the location and acid strength of Br?nsted acid sites in MCM-22 zeolite[J].J Mol Catal,A:Chem,2006,244(1/2):11-19.
[12]Chen Jialing,Liang Tingyu,Li Junfen,et al.Regulation of framework aluminum siting and acid distribution in H-MCM-22by boron incorporation and its effect on the catalytic performance in methanol to hydrocarbons[J].ACS Catal,2016,6(4):2299-2313.
[13]Wang Yanan,Gao Yang,Xie Sujuan,et al.Adjustment of the Al siting in MCM-22 zeolite and its effect on alkylation performance of ethylene with benzene[J].Catal Today,2018,316:71-77.
[14]Zhu Guoqing,Zhao Fangjie,Wang Dayong,et al.Extended effective carbon number concept in the quantitative analysis of multi-ethers using predicted response factors[J].J Chromatogr A,2017,1513:194-200.
[15]李玉阁,曹祖宾,李秀萍,等.有效碳数-内标法计算聚甲氧基二甲醚的含量[J].应用化工,2013,42(9):1729-1733.
[16]张晓宇.聚甲氧基二甲醚的合成与精制研究[D].天津:天津大学,2017.
[17]Ravishankar R,Bhattacharya D,Jacob N E,et al.Characterization and catalytic properties of zeolite MCM-22[J].Microporous Mater,1995,4(1):83-93.
[18]Corma A,Corell C,Pérez-Pariente J,et al.Adsorption and catalytic properties of MCM-22:The influence of zeolite structure[J].Zeolites,1996,16(1):7-14.
[19]Corma A,Corell C,Fornés V,et al.Infrared spectroscopy,thermoprogrammed desorption,and nuclear magnetic resonance study of the acidity,structure,and stability of zeolite MCM-22[J].Zeolites,1995,15(7):576-582.
[20]Kang N Y,Song B S,Lee C W,et al.The effect of Na2SO4salt on the synthesis of ZSM-5 by template free crystallization method[J].Microporous Mesoporous Mater,2009,118(1/3):361-372.
[21]Lawton S L,Fung A S,Kennedy G J,et al.Zeolite MCM-49:A three-dimensional MCM-22 analogue synthesized by in situ crystallization[J].J Phys Chem,1996,100(9):3788-3798.
[22]Xue Zhenzhen,Shang Hongyan,Zhang Zailong,et al.Efficient synthesis of polyoxymethylene dimethyl ethers on Al-SBA-15 catalysts with different Si/Al ratios and pore sizes[J].Energy Fuels,2017,31(1):279-286.
[2]刘康军,张朝峰,李瑞丰.聚甲氧基甲缩醛的最新研究进展[J].化工进展,2013,32(11):2593-2598.
[3]Baranowski C J,Bahmanpour A M,Kr?Cher O.Catalytic synthesis of polyoxymethylene dimethyl ethers(OME):A review[J].Appl Catal,B,2017:407-420.
[4]雷艳华,孙清,陈兆旭,等.合成聚甲醛二甲基醚反应热力学的理论计算[J].化学学报,2009,67(8):767-772.
[5]张向京,武朋涛,蒋子超,等.聚甲醛二甲醚反应热力学分析[J].化学工程,2015,43(4):39-44.
[6]Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences.Method for preparing polymethoxymethylal:US7560599[P].2009-07-14.
[7]Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences.Method for synthesizing polyoxymethylene dimethyl ethers by ionic liquid catalysis:US8344183[P].2013-01-01.
[8]Li Huaju,Song Huanling,Chen Liwei,et al.Designed SO42-/Fe2O3-SiO2 solid acids for polyoxymethylene dimethyl ethers synthesis:The acid sites control and reaction pathways[J].Appl Catal,B,2015,165:466-476.
[9]赵启,王辉,秦张峰,等.分子筛催化剂上甲醇与三聚甲醛缩合制聚甲醛二甲醚[J].燃料化学学报,2011,39(12):918-923.
[10]Bevilacqua M,Meloni D,Sini F,et al.A study of the nature,strength,and accessibility of acid sites of H-MCM-22 zeolite[J].J Phys Chem,C,2008,112(24):9023-9033.
[11]Zhou Danhong,Bao Ying,Yang Mingmei,et al.DFTstudies on the location and acid strength of Br?nsted acid sites in MCM-22 zeolite[J].J Mol Catal,A:Chem,2006,244(1/2):11-19.
[12]Chen Jialing,Liang Tingyu,Li Junfen,et al.Regulation of framework aluminum siting and acid distribution in H-MCM-22by boron incorporation and its effect on the catalytic performance in methanol to hydrocarbons[J].ACS Catal,2016,6(4):2299-2313.
[13]Wang Yanan,Gao Yang,Xie Sujuan,et al.Adjustment of the Al siting in MCM-22 zeolite and its effect on alkylation performance of ethylene with benzene[J].Catal Today,2018,316:71-77.
[14]Zhu Guoqing,Zhao Fangjie,Wang Dayong,et al.Extended effective carbon number concept in the quantitative analysis of multi-ethers using predicted response factors[J].J Chromatogr A,2017,1513:194-200.
[15]李玉阁,曹祖宾,李秀萍,等.有效碳数-内标法计算聚甲氧基二甲醚的含量[J].应用化工,2013,42(9):1729-1733.
[16]张晓宇.聚甲氧基二甲醚的合成与精制研究[D].天津:天津大学,2017.
[17]Ravishankar R,Bhattacharya D,Jacob N E,et al.Characterization and catalytic properties of zeolite MCM-22[J].Microporous Mater,1995,4(1):83-93.
[18]Corma A,Corell C,Pérez-Pariente J,et al.Adsorption and catalytic properties of MCM-22:The influence of zeolite structure[J].Zeolites,1996,16(1):7-14.
[19]Corma A,Corell C,Fornés V,et al.Infrared spectroscopy,thermoprogrammed desorption,and nuclear magnetic resonance study of the acidity,structure,and stability of zeolite MCM-22[J].Zeolites,1995,15(7):576-582.
[20]Kang N Y,Song B S,Lee C W,et al.The effect of Na2SO4salt on the synthesis of ZSM-5 by template free crystallization method[J].Microporous Mesoporous Mater,2009,118(1/3):361-372.
[21]Lawton S L,Fung A S,Kennedy G J,et al.Zeolite MCM-49:A three-dimensional MCM-22 analogue synthesized by in situ crystallization[J].J Phys Chem,1996,100(9):3788-3798.
[22]Xue Zhenzhen,Shang Hongyan,Zhang Zailong,et al.Efficient synthesis of polyoxymethylene dimethyl ethers on Al-SBA-15 catalysts with different Si/Al ratios and pore sizes[J].Energy Fuels,2017,31(1):279-286.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |