四乙基氢氧化铵后晶化处理对ZSM-5分子筛结构及其甲醇制丙烯催化性能的影响
|
摘要
采用四乙基氢氧化铵(TEAOH)溶液对以四丙基氢氧化铵(TPAOH)为模板剂合成的高硅ZSM-5分子筛进行"后晶化"处理,制得晶内扩孔的多级孔ZSM-5分子筛。采用X-射线衍射仪(XRD)、N_2物理吸附、透射电子显微镜(TEM)、氨气程序升温脱附仪(NH_3-TPD)等对母体及改性后的ZSM-5分子筛进行物化性能表征,并采用固定床微反应装置考察其在甲醇制丙烯(MTP)反应中的催化性能。结果表明,TEAOH后晶化处理使高硅ZSM-5分子筛形成晶内介孔,在相对结晶度保留较高的同时,介孔孔容增加超过50%,成为具有微、介孔结构的多级孔分子筛。在反应温度480℃、反应压力0.1 MPa、甲醇/水质量比1/1、甲醇质量空速4.5h-1的条件下,多级孔ZSM-5分子筛的丙烯碳基收率比母体ZSM-5分子筛略有提高,寿命由改性前的25h增加至100h。
Highly siliceous ZSM-5 zeolite synthesized with tetrapropylammonium hydroxide(TPAOH)as structure-directing agent was post-treated by tetraethylammonium hydroxide(TEAOH),to obtain intracrystalline mesopores.Both ZSM-5 and hierarchical ZSM-5 zeolites were characterized by X-ray diffraction(XRD),N_2-adsorption,transmission electron microscope(TEM)and NH_3 temperature-programmed desorption(NH_3-TPD).Methanol to propylene reaction over ZSM-5 and hierarchical ZSM-5 zeolites was carried out in a fixed-bed microreactor.It is shown that TEAOH treatment of high siliceous ZSM-5 generates the intracrystalline mesopore by more than50% with high relative crystallinity because of the participation of tetraethylammonium ion(TEA+).Under the following operating conditions:T=480℃,p=0.1 MPa,m(Methanol)/m(H_2O)=1/1 and methanol mass hourly space velocity MHSV=4.5 h-1,the yield of propylene for hierarchical ZSM-5 zeolite is much higher than that of ZSM-5.Moreover,it exhibits long catalytic lifespan from25 hours to 100 hours.
Highly siliceous ZSM-5 zeolite synthesized with tetrapropylammonium hydroxide(TPAOH)as structure-directing agent was post-treated by tetraethylammonium hydroxide(TEAOH),to obtain intracrystalline mesopores.Both ZSM-5 and hierarchical ZSM-5 zeolites were characterized by X-ray diffraction(XRD),N_2-adsorption,transmission electron microscope(TEM)and NH_3 temperature-programmed desorption(NH_3-TPD).Methanol to propylene reaction over ZSM-5 and hierarchical ZSM-5 zeolites was carried out in a fixed-bed microreactor.It is shown that TEAOH treatment of high siliceous ZSM-5 generates the intracrystalline mesopore by more than50% with high relative crystallinity because of the participation of tetraethylammonium ion(TEA+).Under the following operating conditions:T=480℃,p=0.1 MPa,m(Methanol)/m(H_2O)=1/1 and methanol mass hourly space velocity MHSV=4.5 h-1,the yield of propylene for hierarchical ZSM-5 zeolite is much higher than that of ZSM-5.Moreover,it exhibits long catalytic lifespan from25 hours to 100 hours.
引文
[1]STOCKER M.Methanol-to-hydrocarbons:catalytic materials and their behavior[J].Microporous and Mesoporous Materials,1999,29(1):3-48.
[2]CHEN J Q,BOZZANO A,GLOVER B,et al.Recent advancements in ethylene and propylene production using the UOP/Hydro MTO process[J].Catalysis Today,2005,106(1):103-107.
[3]YOUNG L B,BUTTER S A,KAEDING W W.Shape selective reactions with zeolite catalysts:ⅢSelectivity in xylene isomerization,toluene-methanol alkylation,and toluene disproportionation over ZSM-5zeolite catalysts[J].Journal of Catalysis,1982,76(2):418-432.
[4]CEJKA J,BEKKUM H V,CORMA A,et al.Introduction to zeolite molecular sieves[J].Elsevier Science&Technology,2013,22(4):329-341.
[5]CORMA A.From microporous to mesoporous molecular sieve materials and their use in catalysis[J].Chemical Reviews,1997,97(6):2373-2420.
[6]BARBERA K,BONINO F,BORDIGA S,et al.Structure-deactivation relationship for ZSM-5catalysts governed by framework defects[J].Journal of Catalysis,2011,280(2):196-205.
[7]LEE K Y,KANG M Y,IHM S K.Deactivation by coke deposition on the HZSM-5 catalysts in the methanol-to-hydrocarbon conversion[J].Journal of Physics and Chemistry of Solids,2012,73(12):1542-1545.
[8]AL-KHATTAF S,D’AGOSTINO C,AKHTAR M N,et al.The effect of coke deposition on the activity and selectivity of the HZSM-5zeolite during ethylbenzene alkylation reaction in the presence of ethanol[J].Catalysis Science&Technology,2014,4(4):1017-1027.
[9]张卿,张兰兰,胡思,等.不同铝源合成ZSM-5分子筛及其MTP催化性能[J].石油学报(石油加工),2012,28(增刊1):39-43.(ZHANG Qing,ZHANG Lanlan,HU Si,et al.Effect of aluminum sources on the synthesis of ZSM-5 and their catalytic properties for MTP reaction[J].Acta Petrolei Sinica(Petroleum Processing Section),2012,28(s1):39-43.)
[10]FAN Y,BAO X,LIN X,et al.Acidity adjustment of HZSM-5 zeolites by dealumination and realumination with steaming and citric acid treatments[J].The Journal of Physical Chemistry B,2006,110(31):15411-15416.
[11]DAI C,ZHANG A,LI L,et al.Synthesis of hollow nanocubes and macroporous monoliths of silicalite-1by alkaline treatment[J].Chemistry of Materials,2013,25(21):4197-4205.
[12]GROEN J C,PEFFER L A A,MOULIJN J A,et al.Mesoporosity development in ZSM-5 zeolite upon optimized desilication conditions in alkaline medium[J].Colloids&Surfaces A Physicochemical&Engineering Aspects,2004,241(1-3):53-58.
[13]GROEN J C,PEFFER L A A,MOULIJN J A,et al.On the introduction of intracrystalline mesoporosity in zeolites upon desilication in alkaline medium[J].Microporous&Mesoporous Materials,2004,69(1):29-34.
[14]黄先亮,周继承.二次晶化法修饰改性钛硅分子筛及催化环己酮氨氧化反应[J].化学反应工程与工艺,2007,23(6):553-559.(HUANG Xianliang,ZHOU Jicheng.Study of ammoximation of cyclohexanone over Titanium Silicalites zeolite catalyst synthesized by secondary crystallized method[J].Chemical Reaction Engineering and Technology,2007,23(6):553-559.)
[15]HE Y P,LIU M,DAI C,et al.Modification of nanocrystalline HZSM-5zeolite with tetrapropylammonium hydroxide and its catalytic performance in methanol to gasoline reaction[J].Chinese Journal of Catalysis,2013,34(6):1148-1158.
[16]AHMADPOUR J,TAGHIZADEH M.Selective production of propylene from methanol over high-silica mesoporous ZSM-5 zeolites treated with NaOH and NaOH/tetrapropylammonium hydroxide[J].Comptes Rendus Chimie,2015,18(8):834-847.
[17]王萍,王殿中,冯强,等.一种ZSM-5分子筛的无钠合成方法:CN,102897793A[P].2013-01-30.
[18]STOCKER M.Methanol-to-hydrocarbons:catalytic materials and their behavior[J].Microporous and Mesoporous Materials,1999,29(1):3-48.
[19]CUI T L,LL B,ZHANG W B,et al.Programmable synthesis of mesoporous ZSM-5nanocrystals as selective and stable catalysts for the methanol-to-propylene process[J].Catalysis Science&Technology,2016,6(14):5262-5266.
[20]HU Z,ZHANG H,WANG L,et al.Highly stable boron-modified hierarchical nanocrystalline ZSM-5zeolite for the methanol to propylene reaction[J].Catalysis Science&Technology,2014,4(9):2891-2895.
[21]ILIAS S,KHARE R,MALEK A,et al.A descriptor for the relative propagation of the aromatic-and olefinbased cycles in methanol-to-hydrocarbons conversion on H-ZSM-5[J].Journal of Catalysis,2013,303(13):135-140.
[22]KHARE R,MILLAR D,BHAN A.A mechanistic basis for the effects of crystallite size on light olefin selectivity in methanol-to-hydrocarbons conversion on MFI[J].Journal of Catalysis,2015,321:23-31.
[23]KIM J,CHOI M,RYOO R.Effect of mesoporosity against the deactivation of MFI zeolite catalyst during the methanol-to-hydrocarbon conversion process[J].Journal of Catalysis,2010,269(1):219-228.
[24]BJORGEN M,OLSBYE U,KOLBOE S.Coke precursor formation and zeolite deactivation:Mechanistic insights from hexamethylbenzene conversion[J].Journal of Catalysis,2003,215(1):30-44.
[25]OLSBYE U,SVELLE S,BJORGEN M,et al.Conversion of methanol to hydrocarbons:how zeolite cavity and pore size controls product selectivity[J].Angewandte Chemie International Edition,2012,43(24):5810-5831.
[2]CHEN J Q,BOZZANO A,GLOVER B,et al.Recent advancements in ethylene and propylene production using the UOP/Hydro MTO process[J].Catalysis Today,2005,106(1):103-107.
[3]YOUNG L B,BUTTER S A,KAEDING W W.Shape selective reactions with zeolite catalysts:ⅢSelectivity in xylene isomerization,toluene-methanol alkylation,and toluene disproportionation over ZSM-5zeolite catalysts[J].Journal of Catalysis,1982,76(2):418-432.
[4]CEJKA J,BEKKUM H V,CORMA A,et al.Introduction to zeolite molecular sieves[J].Elsevier Science&Technology,2013,22(4):329-341.
[5]CORMA A.From microporous to mesoporous molecular sieve materials and their use in catalysis[J].Chemical Reviews,1997,97(6):2373-2420.
[6]BARBERA K,BONINO F,BORDIGA S,et al.Structure-deactivation relationship for ZSM-5catalysts governed by framework defects[J].Journal of Catalysis,2011,280(2):196-205.
[7]LEE K Y,KANG M Y,IHM S K.Deactivation by coke deposition on the HZSM-5 catalysts in the methanol-to-hydrocarbon conversion[J].Journal of Physics and Chemistry of Solids,2012,73(12):1542-1545.
[8]AL-KHATTAF S,D’AGOSTINO C,AKHTAR M N,et al.The effect of coke deposition on the activity and selectivity of the HZSM-5zeolite during ethylbenzene alkylation reaction in the presence of ethanol[J].Catalysis Science&Technology,2014,4(4):1017-1027.
[9]张卿,张兰兰,胡思,等.不同铝源合成ZSM-5分子筛及其MTP催化性能[J].石油学报(石油加工),2012,28(增刊1):39-43.(ZHANG Qing,ZHANG Lanlan,HU Si,et al.Effect of aluminum sources on the synthesis of ZSM-5 and their catalytic properties for MTP reaction[J].Acta Petrolei Sinica(Petroleum Processing Section),2012,28(s1):39-43.)
[10]FAN Y,BAO X,LIN X,et al.Acidity adjustment of HZSM-5 zeolites by dealumination and realumination with steaming and citric acid treatments[J].The Journal of Physical Chemistry B,2006,110(31):15411-15416.
[11]DAI C,ZHANG A,LI L,et al.Synthesis of hollow nanocubes and macroporous monoliths of silicalite-1by alkaline treatment[J].Chemistry of Materials,2013,25(21):4197-4205.
[12]GROEN J C,PEFFER L A A,MOULIJN J A,et al.Mesoporosity development in ZSM-5 zeolite upon optimized desilication conditions in alkaline medium[J].Colloids&Surfaces A Physicochemical&Engineering Aspects,2004,241(1-3):53-58.
[13]GROEN J C,PEFFER L A A,MOULIJN J A,et al.On the introduction of intracrystalline mesoporosity in zeolites upon desilication in alkaline medium[J].Microporous&Mesoporous Materials,2004,69(1):29-34.
[14]黄先亮,周继承.二次晶化法修饰改性钛硅分子筛及催化环己酮氨氧化反应[J].化学反应工程与工艺,2007,23(6):553-559.(HUANG Xianliang,ZHOU Jicheng.Study of ammoximation of cyclohexanone over Titanium Silicalites zeolite catalyst synthesized by secondary crystallized method[J].Chemical Reaction Engineering and Technology,2007,23(6):553-559.)
[15]HE Y P,LIU M,DAI C,et al.Modification of nanocrystalline HZSM-5zeolite with tetrapropylammonium hydroxide and its catalytic performance in methanol to gasoline reaction[J].Chinese Journal of Catalysis,2013,34(6):1148-1158.
[16]AHMADPOUR J,TAGHIZADEH M.Selective production of propylene from methanol over high-silica mesoporous ZSM-5 zeolites treated with NaOH and NaOH/tetrapropylammonium hydroxide[J].Comptes Rendus Chimie,2015,18(8):834-847.
[17]王萍,王殿中,冯强,等.一种ZSM-5分子筛的无钠合成方法:CN,102897793A[P].2013-01-30.
[18]STOCKER M.Methanol-to-hydrocarbons:catalytic materials and their behavior[J].Microporous and Mesoporous Materials,1999,29(1):3-48.
[19]CUI T L,LL B,ZHANG W B,et al.Programmable synthesis of mesoporous ZSM-5nanocrystals as selective and stable catalysts for the methanol-to-propylene process[J].Catalysis Science&Technology,2016,6(14):5262-5266.
[20]HU Z,ZHANG H,WANG L,et al.Highly stable boron-modified hierarchical nanocrystalline ZSM-5zeolite for the methanol to propylene reaction[J].Catalysis Science&Technology,2014,4(9):2891-2895.
[21]ILIAS S,KHARE R,MALEK A,et al.A descriptor for the relative propagation of the aromatic-and olefinbased cycles in methanol-to-hydrocarbons conversion on H-ZSM-5[J].Journal of Catalysis,2013,303(13):135-140.
[22]KHARE R,MILLAR D,BHAN A.A mechanistic basis for the effects of crystallite size on light olefin selectivity in methanol-to-hydrocarbons conversion on MFI[J].Journal of Catalysis,2015,321:23-31.
[23]KIM J,CHOI M,RYOO R.Effect of mesoporosity against the deactivation of MFI zeolite catalyst during the methanol-to-hydrocarbon conversion process[J].Journal of Catalysis,2010,269(1):219-228.
[24]BJORGEN M,OLSBYE U,KOLBOE S.Coke precursor formation and zeolite deactivation:Mechanistic insights from hexamethylbenzene conversion[J].Journal of Catalysis,2003,215(1):30-44.
[25]OLSBYE U,SVELLE S,BJORGEN M,et al.Conversion of methanol to hydrocarbons:how zeolite cavity and pore size controls product selectivity[J].Angewandte Chemie International Edition,2012,43(24):5810-5831.