The alkylation mechanism catalyzed by an ionic liquid （as a Lewis acid） may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear....The alkylation mechanism catalyzed by an ionic liquid （as a Lewis acid） may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene （C 6 D 6） with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] ＋H ＋ and [AlHCl 3 ] ＋ ＋[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] ＋ is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] ＋ which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.展开更多
Aiming at deep desulfurization of gasoline,three amphiphilic catalysts [C18H37N(CH3)3]3+x [PMo12-xVxO40](x=1,2,or 3) were prepared and characterized.The amphiphilic vanadium(V)-substituted polyoxometalates were dissol...Aiming at deep desulfurization of gasoline,three amphiphilic catalysts [C18H37N(CH3)3]3+x [PMo12-xVxO40](x=1,2,or 3) were prepared and characterized.The amphiphilic vanadium(V)-substituted polyoxometalates were dissolved in water-immiscible ionic liquid([Bmim]PF6),forming a H2O2-in-[Bmim]PF6 emulsion desulfurization system with 30 m% H2O2 serving as the oxidant.The catalytic oxidation of sulfur-containing model oil has been studied in detail under various reaction conditions using this system.The ionic liquid emulsion system showed high catalytic oxidative activity in the treatment of commodity gasoline.Furthermore,the mechanism of catalytic oxidative desulfurization was also elaborated.展开更多
Bronsted acidic ionic liquids based on imidazolium cation were employed as efficient catalysts and mediums for the ring opening of phthalic anhydride to synthesize half-esters. Good yields, short reaction time and mil...Bronsted acidic ionic liquids based on imidazolium cation were employed as efficient catalysts and mediums for the ring opening of phthalic anhydride to synthesize half-esters. Good yields, short reaction time and mild reaction condition were achieved. Lower acidity of ionic liquid resulted in higher catalytic selectivity in the synthesis of half-esters. The minimum-energy geometries of sulfonic acid-functionalized ionic liquids based on imidazolium cation revealed that their acidities and catalytic selectivity in the synthesis of half-esters were related to their structures.展开更多
Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a hi...Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a highly active metal-free catalyst is a great challenge.Herein,a series of ionic liquids-SBA-15 hybrid catalysts with different functional groups have been developed for the synthesis of DPC under solventfree condition,which are effective and clean instead of the metal-containing catalysts.It is found that in the presence of[SBA-15-IL-OH]Br catalyst,methyl phenyl carbonate(MPC)conversion of 80.5%along with 99.6%DPC selectivity is achieved,the TOF value is thrice higher than the best value reported by using transition metal-based catalysts.Moreover,the catalyst displays remarkable stability and recyclability.This work provides a new idea to design and prepare eco-friendly catalysts in a broad range of applications for the green synthesis of carbonates.展开更多
Poly-α-olefin(PAO)synthetic oil,a regular long-chain alkane produced from the catalytic polymerization ofα-olefin,is a high-quality lubricating base oil with huge market potential.In this study,PAO synthesis based o...Poly-α-olefin(PAO)synthetic oil,a regular long-chain alkane produced from the catalytic polymerization ofα-olefin,is a high-quality lubricating base oil with huge market potential.In this study,PAO synthesis based on the catalytic polymerization of 1-decene using the ionic liquid(IL)[Bmim]_(x)[C_(2)H_(5)NH_(3)]_(1-x)[Al_(2)Cl_(7)]as the catalyst was studied.Compared with the conventional catalyst[Bmim][Al_(2)Cl_(7)],the obtained PAO product incorporates more trimers and tetramers of 1-decene and contains few double-bond end groups,demonstrating a better catalytic system for PAO-10 production.The apparent polymerization kinetics of 1-decene in this catalytic system were studied based on the 1-decene concentration,catalyst concentration,and reaction temperature.An apparent kinetic equation for PAO formation was determined,providing a promising strategy for PAO production using 1-decene polymerization.展开更多
In this paper, the oxidative desulfurization （ODS） system is directly applied to deal with the catalytic oxidation of sulfur compounds of sulfur-containing model oil by dielectric barrier discharge （DBD） plasma in...In this paper, the oxidative desulfurization （ODS） system is directly applied to deal with the catalytic oxidation of sulfur compounds of sulfur-containing model oil by dielectric barrier discharge （DBD） plasma in the presence of air plus an extraction step with the oxidation-treated fuel put over ionic liquid [BMIM]FeC14 （1-butyl-3-methylimidazolium tetrachloroferrate）. This new system exhibited an excellent desulfurization effect. The sulfur content of DBT in diesel oil decreased from 200 ppm to 4.92 ppm （S removal rate up to 97.5%） under the following optimal reaction conditions： air flow rate （v） of 60 mL/min, amplitude of applied voltage （U） on DBD of 16 kV, input frequency （f） of 79 kHz, catalyst amount （w） of 1.25 wt%, reaction time （t） of 10 min. Moreover, a high desulfurization rate was obtained during oxidation of benzothiophene （BT） or 4,6-DMDBT （4,6-dimethyl-dibenzothiophene） under the aforementioned conditions. The oxidation reactivity of different S compounds was decreased in the order of DBT, 4,6-DMDBT and BT. The remarkable advantage of the novel ODS system is that the desulfurization condition applies in the presence of air at ambient conditions without peroxides, aqueous solvent or biphasic oil-aqueous solution system.展开更多
Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide sa...Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide salts. The recyclability of palladium composite catalyst in various ionic liquids was investigated. [Pd(bipy)2][BF4]2 showed a lower catalytic activity than [Pd(bipy)2][PF6]2 in similar conditions, although the catalytic activity of each composite catalyst in ionic liquids still existed after 4 successive recycles. It was shown the catalytic activity of palladium composite catalyst was higher than that of the catalyst formed in situ from palladium acetate, 2,2′-bipyridyl, and HA (A=PF6-, BF4-) in ionic liquids. The effects of volume of ionic liquids, reaction time, and the dosage of benzoquinone on the copolymerization were also studied.展开更多
Various imidazolium and choline-based functional ionic liquids（Ks） comprising different cations and anions were grafted onto Burkholderiacepacia lipase（BCL） through surface amino acids coupling. The catalytic acti...Various imidazolium and choline-based functional ionic liquids（Ks） comprising different cations and anions were grafted onto Burkholderiacepacia lipase（BCL） through surface amino acids coupling. The catalytic activity, thermostability, organic solvent tolerance and adaptability to temperature and pH changes of the modified BCL were then evaluated in olive oil hydrolysis reaction. The results showed that different combinations of cations and anions in ILs had important influence on the catalytic performance of the modified lipases. BCL modified with IL [Choline][H2PO4] was the most improved lipase, in which increases by 1.2 folds in relative activity, 2.5 folds in typi- cal proton solvent（10% methanol, volume fraction）, and 1.4 folds in thermostability（after incubation at 70℃ for 2 h） were achieved in relative toits native form. BCL modified with [HOOCEPEG350[M][BF4] had higher optimal tempe- rature and pH, and better thermosability compared with the native and other modified BCLs. The conformational changes of BCLs were also confirmed by fluorescence spectroscopy and circular dichroism spectroscopy.展开更多
The catalytic characteristics of horse liver alcohol dehydrogenase （HLADH） in the systems involving ionic liquids （ILs） （BMIm·Cl, BMIm·Br, BMIm·PF6, BMIm·BF4 BMIm·OTf and EMIm·Cl） w...The catalytic characteristics of horse liver alcohol dehydrogenase （HLADH） in the systems involving ionic liquids （ILs） （BMIm·Cl, BMIm·Br, BMIm·PF6, BMIm·BF4 BMIm·OTf and EMIm·Cl） were examined. HLADH displayed higher oxidation activity towards ethanol in the systems containing BMIm·Cl, BMIm·Br, EMIm·Cl or BMIm·PF6 with proper content than that in the IL-free buffer. An excessive amount of these ILs in the reaction systems resulted in an obvious decline in enzymatic activity. BMIm·BF4 and BMIm·OTf of any content investigated could considerably inhibit the enzyme. The anions of ILs showed significant effect on the activity, kinetic parameters and activation energy of HLADH-mediated ethanol oxidation. Additionally, BMIm·Cl, BMIm·Br, EMIm·Cl and BMIm·PF6 boosted markedly the thermostability of HLADH, while the enzyme was less thermostable in BMIm·BF4 or BMIm·OTf-containing systems. The associated conformational changes in HLADH caused by ILs were examined by UV technique.展开更多
The spectral structures of acetamide-AlCl_(3)-based ionic liquid(IL)analogs were determined in detail through IR,NMR,and Raman spectroscopy.IR spectroscopy showed that 0.65AA-1.0AlCl_(3) was the coordination structure...The spectral structures of acetamide-AlCl_(3)-based ionic liquid(IL)analogs were determined in detail through IR,NMR,and Raman spectroscopy.IR spectroscopy showed that 0.65AA-1.0AlCl_(3) was the coordination structure of Al and O atoms because of the resonance structure of acetamide.The mutual verification of the results of ^(27)Al NMR and ^(1)H NMR indicated that acetamide coexisted mainly in the form of cationic Al species and molecular Al species in xAA-1.0AlCl_(3),and AA/AlCl_(3) molar ratio affected the transformation of cationic Al species to molecular Al species.xAA-1.0AlCl_(3) was used as a green acidic catalyst for isobutene oligomerization,and the effects of AA/AlCl_(3) molar ratio,reaction temperature,reaction time,and volumetric ratio between IL analog and isobutene on product distribution were investigated.Optimal reaction conditions were AA/AlCl_(3) molar ratio of 0.75,reaction temperature of 60 C,reaction time of 30 min,and catalyst/i-C4¼volumetric ratio of 1.4 v/v.Under optimal conditions,isobutene conversion,(C8^(-)+C12^(-))selectivity,(C16^(-)+C20^(-))selectivity,and by-product selectivity were 85.26,80.20,6.80,and 13.00 wt%,respectively。展开更多
基金financial support from the National Natural Science Foundation of China (NSFC,2052010)
文摘The alkylation mechanism catalyzed by an ionic liquid （as a Lewis acid） may be different from the traditional alkylation mechanism catalyzed by Br nsted acid,especially as their initiation steps are still not clear.In this paper,an isotope exchange method is used to investigate the catalytic mechanism of AlCl 3 /butyl-methyl-imidazolium chloride ionic liquid in the alkylation of benzene with 1-dodecene.The proposed catalytic mechanism was confirmed by analysis of ionic liquid before and after reaction and of the alkylation products of deuterated benzene （C 6 D 6） with 1-dodecene.The proposed mechanism consists of the equilibrium reaction between [Al 2 Cl 7 ] ＋H ＋ and [AlHCl 3 ] ＋ ＋[AlCl 4 ],in which the Br nsted acid [AlHCl 3 ] ＋ is supplied by the reaction of 2-H on the imidazolium ring and [Al 2 Cl 7 ].The alkylation reaction is initiated by the Br nsted acid [AlHCl 3 ] ＋ which reacts with 1-dodecene to form a carbonium ion,then the carbonium ion reacts with benzene to form an unstable σ complex,leading to the formation of 2-phenyldodecane.
基金the National Nature Science Foundation of China(No.51077013,50873026)Production and Research Prospective Joint Project of Jiangsu Province of China(BY2009153)+2 种基金the Key Program for the Scientific Research Guiding Fund of Basic Scientific Research Operation Expenditure,Southeast University(3207040103)333 High-level Talent Training Project,Jiangsu Province of China (BRA2010033)Student Research Training Program of Southeast University(No.091028644) for financial support
文摘Aiming at deep desulfurization of gasoline,three amphiphilic catalysts [C18H37N(CH3)3]3+x [PMo12-xVxO40](x=1,2,or 3) were prepared and characterized.The amphiphilic vanadium(V)-substituted polyoxometalates were dissolved in water-immiscible ionic liquid([Bmim]PF6),forming a H2O2-in-[Bmim]PF6 emulsion desulfurization system with 30 m% H2O2 serving as the oxidant.The catalytic oxidation of sulfur-containing model oil has been studied in detail under various reaction conditions using this system.The ionic liquid emulsion system showed high catalytic oxidative activity in the treatment of commodity gasoline.Furthermore,the mechanism of catalytic oxidative desulfurization was also elaborated.
基金Supported by the Key Project of Chinese Ministry of Education (No 105075)the National Natural Science Foundation of China (No 20503016)
文摘Bronsted acidic ionic liquids based on imidazolium cation were employed as efficient catalysts and mediums for the ring opening of phthalic anhydride to synthesize half-esters. Good yields, short reaction time and mild reaction condition were achieved. Lower acidity of ionic liquid resulted in higher catalytic selectivity in the synthesis of half-esters. The minimum-energy geometries of sulfonic acid-functionalized ionic liquids based on imidazolium cation revealed that their acidities and catalytic selectivity in the synthesis of half-esters were related to their structures.
基金support from the National Natural Science Foundation of China(No.21808048 and U1704251)Training Plan for University's Young Backbone Teachers of Henan Province(2021GGJS121)+5 种基金Program for Science&Technology Innovation Talents in Universities of Henan Province(23HASTIT014)Postgraduate Education Reform and Quality Improvement Project of Henan Province(YJS2022KC22)Project funded by China Postdoctoral Science Foundation(No.2018M632782)Project funded by Postdoctoral Research Grant in Henan Province(No.001802030)Key Project of Science and Technology Program of Henan Province(No.222102230109,212102310330 and 182102210050)the Science Research Start-up Fund of Henan Institute of Science and Technology(No.2015031).
文摘Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a highly active metal-free catalyst is a great challenge.Herein,a series of ionic liquids-SBA-15 hybrid catalysts with different functional groups have been developed for the synthesis of DPC under solventfree condition,which are effective and clean instead of the metal-containing catalysts.It is found that in the presence of[SBA-15-IL-OH]Br catalyst,methyl phenyl carbonate(MPC)conversion of 80.5%along with 99.6%DPC selectivity is achieved,the TOF value is thrice higher than the best value reported by using transition metal-based catalysts.Moreover,the catalyst displays remarkable stability and recyclability.This work provides a new idea to design and prepare eco-friendly catalysts in a broad range of applications for the green synthesis of carbonates.
基金supported by the Key Research and Development Program of Ningxia Autonomous Region (No.2023BFE01001)Tianjin Science and Technology Program (Nos.22ZYJDSS00060+2 种基金22YDTPJC00920)Program for Tianjin Innovative Research Team in Universities (No.TD13-5031)Tianjin 131 Research Team of Innovative Talents。
文摘Poly-α-olefin(PAO)synthetic oil,a regular long-chain alkane produced from the catalytic polymerization ofα-olefin,is a high-quality lubricating base oil with huge market potential.In this study,PAO synthesis based on the catalytic polymerization of 1-decene using the ionic liquid(IL)[Bmim]_(x)[C_(2)H_(5)NH_(3)]_(1-x)[Al_(2)Cl_(7)]as the catalyst was studied.Compared with the conventional catalyst[Bmim][Al_(2)Cl_(7)],the obtained PAO product incorporates more trimers and tetramers of 1-decene and contains few double-bond end groups,demonstrating a better catalytic system for PAO-10 production.The apparent polymerization kinetics of 1-decene in this catalytic system were studied based on the 1-decene concentration,catalyst concentration,and reaction temperature.An apparent kinetic equation for PAO formation was determined,providing a promising strategy for PAO production using 1-decene polymerization.
基金supported by National Natural Science Foundation of China(No.21063012)the Ministry of Education Innovation Team of China(No.IRT1161)
文摘In this paper, the oxidative desulfurization （ODS） system is directly applied to deal with the catalytic oxidation of sulfur compounds of sulfur-containing model oil by dielectric barrier discharge （DBD） plasma in the presence of air plus an extraction step with the oxidation-treated fuel put over ionic liquid [BMIM]FeC14 （1-butyl-3-methylimidazolium tetrachloroferrate）. This new system exhibited an excellent desulfurization effect. The sulfur content of DBT in diesel oil decreased from 200 ppm to 4.92 ppm （S removal rate up to 97.5%） under the following optimal reaction conditions： air flow rate （v） of 60 mL/min, amplitude of applied voltage （U） on DBD of 16 kV, input frequency （f） of 79 kHz, catalyst amount （w） of 1.25 wt%, reaction time （t） of 10 min. Moreover, a high desulfurization rate was obtained during oxidation of benzothiophene （BT） or 4,6-DMDBT （4,6-dimethyl-dibenzothiophene） under the aforementioned conditions. The oxidation reactivity of different S compounds was decreased in the order of DBT, 4,6-DMDBT and BT. The remarkable advantage of the novel ODS system is that the desulfurization condition applies in the presence of air at ambient conditions without peroxides, aqueous solvent or biphasic oil-aqueous solution system.
基金National Natural Science Foundation of China (No.20476080)Natural Science Foundation of Tianjin (No.07JCYBJC00600)
文摘Room temperature ionic liquids as solvents for palladium-catalyzed copolymerization of carbon monoxide and styrene were prepared by reaction of aqueous lead tetrafluoroborate with correspond-ing chloride or bromide salts. The recyclability of palladium composite catalyst in various ionic liquids was investigated. [Pd(bipy)2][BF4]2 showed a lower catalytic activity than [Pd(bipy)2][PF6]2 in similar conditions, although the catalytic activity of each composite catalyst in ionic liquids still existed after 4 successive recycles. It was shown the catalytic activity of palladium composite catalyst was higher than that of the catalyst formed in situ from palladium acetate, 2,2′-bipyridyl, and HA (A=PF6-, BF4-) in ionic liquids. The effects of volume of ionic liquids, reaction time, and the dosage of benzoquinone on the copolymerization were also studied.
文摘Various imidazolium and choline-based functional ionic liquids（Ks） comprising different cations and anions were grafted onto Burkholderiacepacia lipase（BCL） through surface amino acids coupling. The catalytic activity, thermostability, organic solvent tolerance and adaptability to temperature and pH changes of the modified BCL were then evaluated in olive oil hydrolysis reaction. The results showed that different combinations of cations and anions in ILs had important influence on the catalytic performance of the modified lipases. BCL modified with IL [Choline][H2PO4] was the most improved lipase, in which increases by 1.2 folds in relative activity, 2.5 folds in typi- cal proton solvent（10% methanol, volume fraction）, and 1.4 folds in thermostability（after incubation at 70℃ for 2 h） were achieved in relative toits native form. BCL modified with [HOOCEPEG350[M][BF4] had higher optimal tempe- rature and pH, and better thermosability compared with the native and other modified BCLs. The conformational changes of BCLs were also confirmed by fluorescence spectroscopy and circular dichroism spectroscopy.
基金Project supported by the National Natural Science Foundation of China （No. 20406006） and Department of Education of Fujian Province （No. JB04028）.
文摘The catalytic characteristics of horse liver alcohol dehydrogenase （HLADH） in the systems involving ionic liquids （ILs） （BMIm·Cl, BMIm·Br, BMIm·PF6, BMIm·BF4 BMIm·OTf and EMIm·Cl） were examined. HLADH displayed higher oxidation activity towards ethanol in the systems containing BMIm·Cl, BMIm·Br, EMIm·Cl or BMIm·PF6 with proper content than that in the IL-free buffer. An excessive amount of these ILs in the reaction systems resulted in an obvious decline in enzymatic activity. BMIm·BF4 and BMIm·OTf of any content investigated could considerably inhibit the enzyme. The anions of ILs showed significant effect on the activity, kinetic parameters and activation energy of HLADH-mediated ethanol oxidation. Additionally, BMIm·Cl, BMIm·Br, EMIm·Cl and BMIm·PF6 boosted markedly the thermostability of HLADH, while the enzyme was less thermostable in BMIm·BF4 or BMIm·OTf-containing systems. The associated conformational changes in HLADH caused by ILs were examined by UV technique.
基金support of the National Natural Science Foundation of China(No.21802047)the Scientific Research Funds of Huaqiao University(No.600005-Z17Y0073),Xiamen,China.
文摘The spectral structures of acetamide-AlCl_(3)-based ionic liquid(IL)analogs were determined in detail through IR,NMR,and Raman spectroscopy.IR spectroscopy showed that 0.65AA-1.0AlCl_(3) was the coordination structure of Al and O atoms because of the resonance structure of acetamide.The mutual verification of the results of ^(27)Al NMR and ^(1)H NMR indicated that acetamide coexisted mainly in the form of cationic Al species and molecular Al species in xAA-1.0AlCl_(3),and AA/AlCl_(3) molar ratio affected the transformation of cationic Al species to molecular Al species.xAA-1.0AlCl_(3) was used as a green acidic catalyst for isobutene oligomerization,and the effects of AA/AlCl_(3) molar ratio,reaction temperature,reaction time,and volumetric ratio between IL analog and isobutene on product distribution were investigated.Optimal reaction conditions were AA/AlCl_(3) molar ratio of 0.75,reaction temperature of 60 C,reaction time of 30 min,and catalyst/i-C4¼volumetric ratio of 1.4 v/v.Under optimal conditions,isobutene conversion,(C8^(-)+C12^(-))selectivity,(C16^(-)+C20^(-))selectivity,and by-product selectivity were 85.26,80.20,6.80,and 13.00 wt%,respectively。
