Solid acid catalysts are widely used in the production of various high-value added and industrially important chemicals.Although the use of organosilicon compounds to modify the vacancy site has been extensively studi...Solid acid catalysts are widely used in the production of various high-value added and industrially important chemicals.Although the use of organosilicon compounds to modify the vacancy site has been extensively studied,the covalent tethering-SO_(3)H functionalized organosilicon modified polyoxometalates(POMs)has been rarely reported.In this work,two catalysts(TBA_(4)[SiW_(11)O_(39)(O(SiC_(3)H_(6)SO_(3)H)_(2))](compound 2)and TBA_(4)[SiW_(11)O_(39)(O(SiC_(8)H_(8)SO_(3)H)_(2))](compound 3))were synthesized successfully through covalently grafting different sulfonic acid(-SO_(3)H)groups onto[SiW_(11)O_(39)]^(8−)cluster,respectively.Compound 2 was achieved by surface grafting and in situ oxidation(3-mercaptopropyl)-trimethoxysilane,while compound 3 was achieved by surface grafting of 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane.Strong Brønsted acid strength of compounds 2 and 3 can be demonstrated by different methods including potentiometric titration,pyridine adsorption studies,and the ^(31)P trimethylphosphine oxides(TMPO)nuclear magnetic resonance(NMR).The systematic investigation of the relationship among POM structures,acid strength,and electron density was carried out based on density functional theory(DFT)calculation and experimental results,which revealed that covalent modification of compounds 2 and 3 decreased the electron density of the O-H bond,and promoted the release of H^(+).When applied in hydroxyalkylation/alkylation(HAA)reaction of 2-methylfuran(2-MF)with cyclohexanone,compound 2 exhibited better catalytic performance with conversion of ~93%,monocyclic fuel precursors(1a)yield of 79.9% and selectivity of 85.7% than compound 3,which can be attributed to strong Brønsted acid and the intramolecular hydrogen-bonding interactions between the neighboring -SO_(3)H moieties in compound 2.Finally,compound 2 also showed excellent catalytic activity in the HAA reaction of 2-MF with several different aldehydes and ketones(e.g.,furfuraldehyde,5-methylfurfuraldehyde,acetone,butyraldehyde and 4-methoxybenzaldehyde).This result opens a new pathway for design and fabrication of novel solid acid catalysts.展开更多
Catalytic synthesis of m-diethylbenzene(m-DEB)through alkylation of ethylbenzene(EB)may be a promising alternative route in comparison with traditional rectification of mixed DEB,for which the top priority is to devel...Catalytic synthesis of m-diethylbenzene(m-DEB)through alkylation of ethylbenzene(EB)may be a promising alternative route in comparison with traditional rectification of mixed DEB,for which the top priority is to develop efficient and stable heterogeneous catalysts.Here,the spherical nano-ZSM-5 zeolite with abundant intergranular mesoporous is synthesized by the seed-mediated growth method for alkylation of EB with ethanol to produce m-DEB.The results show that the spherical nano-ZSM-5 zeolite exhibits better stability and higher alkylation activity at a lower temperature than those of commercial micropore ZSM-5.And then,the spherical nano-ZSM-5 is further modified by La_(2)O_(3) through acid treatment followed by immersion method.The acid treatment causes nano-ZSM-5 to exhibit the increased pore size but decreased the acid sites,and subsequent La_(2)O_(3) loading reintroduces the weak acid sites.As a result,the HNO_(3)-La_(2)O_(3)-modified catalyst exhibits a slight increase in EB conversion and DEB yield in comparison with unmodified one,and meanwhile,it still maintains high m-DEB selectivity.The catalyst after acid treatment achieves higher catalytic stability besides maintaining the high alkylation activity of EB with ethanol.The present study on the spherical nano-HZSM-5 zeolite and its modification catalyst with excellent alkylation ability provides new insights into the production of mDEB.展开更多
Abstract A cylindrical pore model was used to represent approximately the pore of β-zeolite catalyst that had been used in the alkylation of benzene with ethylene and spherical Lennard-Jones molecules represented the...Abstract A cylindrical pore model was used to represent approximately the pore of β-zeolite catalyst that had been used in the alkylation of benzene with ethylene and spherical Lennard-Jones molecules represented the components of the reaction system-ethylene, benzene and ethylbenzene. The dual control volume-grand canonical molecular dynamics (DCV-GCMD) method was used to simulate the adsorption and transport properties of three components under reaction in the cylindrical pore at 250℃ and 270℃ in the pressure range from 1 MPa to 8 MPa. The state map of the reactant mixture in the bulk phase could be divided into several different regions around its critical points. The simulated adsorption and transport properties in the pore were compared between the different near-critical regions. The thorough analysis suggested that the high pressure liquid region is the most suitable region for the alkylation reaction of benzene under the near-critical condition.展开更多
For efficient removal of thiophenic sulfur （S-） compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization （OADS）, in which oil insoluble chlorinated polymer such as polyvinyl ch...For efficient removal of thiophenic sulfur （S-） compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization （OADS）, in which oil insoluble chlorinated polymer such as polyvinyl chlo- ride （PVC） is used as the alkylating regent with Lewis acid as catalyst. The aromatic S-compounds are grafted to the polymer through Friedel-Crafts reaction and removed facilely along with the polymer. The OADS mechanism is identified by scanning electron microscope and analyzer with surface area and pore size of the polymer. The influ- ence of some factors on the OADS is studied, e.g. the type and amount of chlorinated polymers and Lewis acids. It is nroved that thionhene and benzothioDhene can be removed efficiently from oil by PVC＋AlCl3 mixture even in the presence of 25% （by mass） of benzene due to the synergetic effects of the adsorptive desulfurization of AlCl3 and the alkylation desulfurization of PVC.展开更多
With the development of coal chemical industry,large amounts of naphthalene and n-butene are produced,and converting them into high value-added products through alkylation has gained particular importance and interest...With the development of coal chemical industry,large amounts of naphthalene and n-butene are produced,and converting them into high value-added products through alkylation has gained particular importance and interest.In this work,liquid coordination complexes(LCCs)were used as acid catalysts for the first time in the naphthalene alkylation reaction under mild conditions to obtain multibutylnaphthalenes with high yield.Various reaction conditions were thoroughly investigated.The LCC consisting of urea and AlCl_(3) showed excellent catalytic performance under optimal reaction conditions,giving 100%conversion of naphthalene and 99.66%selectivity towards multi-butylnaphthalenes.Combining the catalyst properties and catalytic results,a plausible reaction mechanism was proposed.The lubricating properties of the synthesized products were investigated for their potential application as lubricating base oils.The synthesized multi-butylnaphthalenes showed comparable physicochemical properties and tribological performances as the commercial cycloalkyl base oil.展开更多
The reactions of α-(alkoxysilyl)allyl anions 4 with electrophiles were studied. α-Alkylation with alkyl halides was favoured, whereas γ-selection was achieved in the reaction with aldehydes.
Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki r...Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki reaction.The structures of the new compounds synthesized were confirmed by elemental analysis,IR,1H NMR and MS.This new method makes a feature of low cost and readily available starting material,fewer steps,mild condition,easiness to operate and higher yield.展开更多
A new approach to allylic alkylation is realized using an atomically dispersed palladium catalyst(Pd1/TiO2-EG).Unlike conventional methods that require derivation of substrates and utilization of additives,this method...A new approach to allylic alkylation is realized using an atomically dispersed palladium catalyst(Pd1/TiO2-EG).Unlike conventional methods that require derivation of substrates and utilization of additives,this method allows for direct allylic alkylation from allylic alcohols,producing H2O as the sole by-product.The catalyst's high efficiency is attributed to the local hydrogen bonding at the or-ganic-inorganic interface(Pd-EG interface),facilitating hydroxyl group activation forη3π-allyl complex formation.The system demonstrates successful direct C—O and C—C coupling reactions with high selectivity,requiring no additives.This study highlights the potential of supported atomically dispersed catalysts for greener and more efficient catalysis,meanwhile,offers unique insights into the distinct behavior of atomically dispersed catalysts in comparison to homogeneous or nanoparticle-based catalysts.展开更多
基金supported by the National Key Research and Development Program of China(2017YFB0307303)the National Nature Science Foundation of China(21625101,21521005)the Fundamental Research Funds for the Central Universities(XK1802-6,XK1803-05,XK1902,12060093063)。
文摘Solid acid catalysts are widely used in the production of various high-value added and industrially important chemicals.Although the use of organosilicon compounds to modify the vacancy site has been extensively studied,the covalent tethering-SO_(3)H functionalized organosilicon modified polyoxometalates(POMs)has been rarely reported.In this work,two catalysts(TBA_(4)[SiW_(11)O_(39)(O(SiC_(3)H_(6)SO_(3)H)_(2))](compound 2)and TBA_(4)[SiW_(11)O_(39)(O(SiC_(8)H_(8)SO_(3)H)_(2))](compound 3))were synthesized successfully through covalently grafting different sulfonic acid(-SO_(3)H)groups onto[SiW_(11)O_(39)]^(8−)cluster,respectively.Compound 2 was achieved by surface grafting and in situ oxidation(3-mercaptopropyl)-trimethoxysilane,while compound 3 was achieved by surface grafting of 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane.Strong Brønsted acid strength of compounds 2 and 3 can be demonstrated by different methods including potentiometric titration,pyridine adsorption studies,and the ^(31)P trimethylphosphine oxides(TMPO)nuclear magnetic resonance(NMR).The systematic investigation of the relationship among POM structures,acid strength,and electron density was carried out based on density functional theory(DFT)calculation and experimental results,which revealed that covalent modification of compounds 2 and 3 decreased the electron density of the O-H bond,and promoted the release of H^(+).When applied in hydroxyalkylation/alkylation(HAA)reaction of 2-methylfuran(2-MF)with cyclohexanone,compound 2 exhibited better catalytic performance with conversion of ~93%,monocyclic fuel precursors(1a)yield of 79.9% and selectivity of 85.7% than compound 3,which can be attributed to strong Brønsted acid and the intramolecular hydrogen-bonding interactions between the neighboring -SO_(3)H moieties in compound 2.Finally,compound 2 also showed excellent catalytic activity in the HAA reaction of 2-MF with several different aldehydes and ketones(e.g.,furfuraldehyde,5-methylfurfuraldehyde,acetone,butyraldehyde and 4-methoxybenzaldehyde).This result opens a new pathway for design and fabrication of novel solid acid catalysts.
基金Research support is from the Service Local Project of the Education Department of Liaoning Province(LJKMZ22021404,LF2019002 and LJKMZ22021423)the“Transformational Technologies for Clean Energy and Demonstration”,Strategic Priority Research Program of the Chinese Academy of Sciences,(XDA 21030500).
文摘Catalytic synthesis of m-diethylbenzene(m-DEB)through alkylation of ethylbenzene(EB)may be a promising alternative route in comparison with traditional rectification of mixed DEB,for which the top priority is to develop efficient and stable heterogeneous catalysts.Here,the spherical nano-ZSM-5 zeolite with abundant intergranular mesoporous is synthesized by the seed-mediated growth method for alkylation of EB with ethanol to produce m-DEB.The results show that the spherical nano-ZSM-5 zeolite exhibits better stability and higher alkylation activity at a lower temperature than those of commercial micropore ZSM-5.And then,the spherical nano-ZSM-5 is further modified by La_(2)O_(3) through acid treatment followed by immersion method.The acid treatment causes nano-ZSM-5 to exhibit the increased pore size but decreased the acid sites,and subsequent La_(2)O_(3) loading reintroduces the weak acid sites.As a result,the HNO_(3)-La_(2)O_(3)-modified catalyst exhibits a slight increase in EB conversion and DEB yield in comparison with unmodified one,and meanwhile,it still maintains high m-DEB selectivity.The catalyst after acid treatment achieves higher catalytic stability besides maintaining the high alkylation activity of EB with ethanol.The present study on the spherical nano-HZSM-5 zeolite and its modification catalyst with excellent alkylation ability provides new insights into the production of mDEB.
基金Supported by the National Natural Science Foundation of China (No. 20236010) E-institute of Shanghai High Institution Grid (No. 200303).
文摘Abstract A cylindrical pore model was used to represent approximately the pore of β-zeolite catalyst that had been used in the alkylation of benzene with ethylene and spherical Lennard-Jones molecules represented the components of the reaction system-ethylene, benzene and ethylbenzene. The dual control volume-grand canonical molecular dynamics (DCV-GCMD) method was used to simulate the adsorption and transport properties of three components under reaction in the cylindrical pore at 250℃ and 270℃ in the pressure range from 1 MPa to 8 MPa. The state map of the reactant mixture in the bulk phase could be divided into several different regions around its critical points. The simulated adsorption and transport properties in the pore were compared between the different near-critical regions. The thorough analysis suggested that the high pressure liquid region is the most suitable region for the alkylation reaction of benzene under the near-critical condition.
基金Supported by the National Natural Science Foundation of China(21376011)the Fundamental Research Foundation of Sinopec(X505015)
文摘For efficient removal of thiophenic sulfur （S-） compounds from oils, a novel method is proposed here, i.e. one-pot alkylation desulfurization （OADS）, in which oil insoluble chlorinated polymer such as polyvinyl chlo- ride （PVC） is used as the alkylating regent with Lewis acid as catalyst. The aromatic S-compounds are grafted to the polymer through Friedel-Crafts reaction and removed facilely along with the polymer. The OADS mechanism is identified by scanning electron microscope and analyzer with surface area and pore size of the polymer. The influ- ence of some factors on the OADS is studied, e.g. the type and amount of chlorinated polymers and Lewis acids. It is nroved that thionhene and benzothioDhene can be removed efficiently from oil by PVC＋AlCl3 mixture even in the presence of 25% （by mass） of benzene due to the synergetic effects of the adsorptive desulfurization of AlCl3 and the alkylation desulfurization of PVC.
基金the National Natural Science Foundation of China(U1910202,21978194 and 21603256)the Natural Science Foundation of Shanxi Province(201801D121055)Program for the Shanxi Young Sanjin Scholar.
文摘With the development of coal chemical industry,large amounts of naphthalene and n-butene are produced,and converting them into high value-added products through alkylation has gained particular importance and interest.In this work,liquid coordination complexes(LCCs)were used as acid catalysts for the first time in the naphthalene alkylation reaction under mild conditions to obtain multibutylnaphthalenes with high yield.Various reaction conditions were thoroughly investigated.The LCC consisting of urea and AlCl_(3) showed excellent catalytic performance under optimal reaction conditions,giving 100%conversion of naphthalene and 99.66%selectivity towards multi-butylnaphthalenes.Combining the catalyst properties and catalytic results,a plausible reaction mechanism was proposed.The lubricating properties of the synthesized products were investigated for their potential application as lubricating base oils.The synthesized multi-butylnaphthalenes showed comparable physicochemical properties and tribological performances as the commercial cycloalkyl base oil.
文摘The reactions of α-(alkoxysilyl)allyl anions 4 with electrophiles were studied. α-Alkylation with alkyl halides was favoured, whereas γ-selection was achieved in the reaction with aldehydes.
文摘Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki reaction.The structures of the new compounds synthesized were confirmed by elemental analysis,IR,1H NMR and MS.This new method makes a feature of low cost and readily available starting material,fewer steps,mild condition,easiness to operate and higher yield.
基金support from National Key R&D Program of China (2022YFA1504500)the National Natural Science Foundation of China (grant no.92261207,and NSFC Center for Single-Atom Catalysis under grant no.22388102)+4 种基金the New Cornerstone Science Foundation.P.L.acknowledges the Shanghai Pujiang Talent Program (No.21PJ1410400)the Start-up Funding and the Double First-Class Initiative Fund of ShanghaiTech University.R.Q.acknowledges support from the Young Scientists Fund of the National Natural Science Foundation of China (22202164)the Natural Science Foundation of Fujian Province (2023J05006)the Fundamental Research Funds for the Central Universities (20720230002)the Fujian Provincial Chemistry Discipline Alliance.
文摘A new approach to allylic alkylation is realized using an atomically dispersed palladium catalyst(Pd1/TiO2-EG).Unlike conventional methods that require derivation of substrates and utilization of additives,this method allows for direct allylic alkylation from allylic alcohols,producing H2O as the sole by-product.The catalyst's high efficiency is attributed to the local hydrogen bonding at the or-ganic-inorganic interface(Pd-EG interface),facilitating hydroxyl group activation forη3π-allyl complex formation.The system demonstrates successful direct C—O and C—C coupling reactions with high selectivity,requiring no additives.This study highlights the potential of supported atomically dispersed catalysts for greener and more efficient catalysis,meanwhile,offers unique insights into the distinct behavior of atomically dispersed catalysts in comparison to homogeneous or nanoparticle-based catalysts.
