The carboxylic functionalized ionic liquid was immobilized on the molecular sieve(MCM-22)and then applied in the catalytic synthe-sis of ethyl methyl carbonate(EMC)via transesterification of dimethyl carbonate(DMC)wit...The carboxylic functionalized ionic liquid was immobilized on the molecular sieve(MCM-22)and then applied in the catalytic synthe-sis of ethyl methyl carbonate(EMC)via transesterification of dimethyl carbonate(DMC)with ethanol.Combined characterization results of FT-IR,XRD and TG suggest that the ILs had been immobilized on molecular sieve MCM-22.The influences of reaction temperature,time,and the mass ratio of MCM-22-CPTES-MIL/Ca O have also been investigated in detail.The catalytic tests demonstrated that MCM-22-CPTES-MIL/Ca O could catalyze the transesterification of DMC and ethanol with high efficiency,superior to those results of the heterogeneous catalysts reported previously.展开更多
A large number of surplus glycerol from the biodiesel production can be used as renewable feedstock to produce glycerol carbonate. In this paper, a series of guanidine-based ionic liquids were synthesized to catalyze ...A large number of surplus glycerol from the biodiesel production can be used as renewable feedstock to produce glycerol carbonate. In this paper, a series of guanidine-based ionic liquids were synthesized to catalyze the transesterification of glycerol and dimethyl carbonate. The tunable basicity and the anion–cation cooperative effect were responsible for the obtained results. The [TMG][TFE] showed the best activity turnover frequency(TOF)of 1754.0 h^(-1), glycerol(GL) conversion of 91.8%, glycerol carbonate(GC) selectivity of 95.5%) at 80 °C with 0.1 mol% catalyst for 30 min. The reaction mechanism of the transesterification was also proposed.展开更多
Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium ...Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol.However,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and recovery.To address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and functionalization.These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics.Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC.It was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant changes.The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.展开更多
In the present study,the transesterification of glycerol trioleate was carried out over a basic ionic liquid,1-butyl-3- methylimidazolium hydroxide（[Bmim]OH） and an 87.2%yield of methyl ester was achieved.The produc...In the present study,the transesterification of glycerol trioleate was carried out over a basic ionic liquid,1-butyl-3- methylimidazolium hydroxide（[Bmim]OH） and an 87.2%yield of methyl ester was achieved.The product was isolated through simple decantation from the biphasic system due to the immiscibility of[BmimJOH with ester.[Bmim]OH can be easily recovered and reused six times without dramatic decrease in ester yield.展开更多
The synthesis of dimethyl carbonate(DMC)via transesterification of ethylene carbonate(EC)and methanol(MeOH)was an environmental and practical strategy.Herein,poly(ionic liquid)s(PILs)with swelling abilities were synth...The synthesis of dimethyl carbonate(DMC)via transesterification of ethylene carbonate(EC)and methanol(MeOH)was an environmental and practical strategy.Herein,poly(ionic liquid)s(PILs)with swelling abilities were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,sodium 4-vinylbenzoate and cross-linker(1,8-triethylene glycoldiyl-3,3'-divinylimidazolium bromide([(EG)_(3)-DVIm]Br_(2)).The swelling abilities of PILs in various solvents were measured,and PILs could swell in methanol(MeOH).The swelling ability of PILs in MeOH could be modulated by changing the cross-linker content and chain length of 3-alkyl-substituents on imidazolium.The swollen state of PILs in MeOH presented a porous cross-linked network structure observed by the cryo-scanning electron microscope(cryo-SEM).The swelling PILs were used to catalyze the transesterification of ethylene carbonate(EC)and MeOH to prepare the DMC,and the catalytic activities was correlated with the swelling abilities of PILs.The PIL with 3-butyl-substituent and 2.5 mol%cross-linker(poly[VBIm-VBA-DVIm]-2.5%)had the highest swelling ratio(Q=12.4(g/g))in MeOH and EC mixed solvents and exhibited excellent catalytic activities,which was similar to corresponding homogeneous ionic liquid.Furthermore,the catalyst could be reused up to seven runs without any considerable loss of its initial activity.展开更多
In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl...In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl carbonate.At 70℃,up to 97%conversion of ethylene carbonate and 91%yield of dimethyl ca rbonate were obtained with 1 mol%[DBUH][Im](relative to ethylene carbonate)as catalyst in 2 h.Even at room temperature,the conversion of ethylene carbonate can reach 94%and the yield of dimethyl carbonate can approach 81%for 6 h.Catalytic mechanism investigation showed the high catalytic efficiency of this ionic liquid results from the synergistic activation effect,wherein the cation can activate ethylene carbonate and the anion can activate methanol through hydrogen bond formatio n.Although the reusability of the ionic liquid need to be further improved,high efficiency and comme rcial availability of[DBUH][Im]render it a promising catalyst for the preparation of dimethyl carbonate.展开更多
基金Supported by the Educational Department of Liaoning Province(LZGD2020005)Liaoning Province Innovation and Entrepreneurship Training Project。
文摘The carboxylic functionalized ionic liquid was immobilized on the molecular sieve(MCM-22)and then applied in the catalytic synthe-sis of ethyl methyl carbonate(EMC)via transesterification of dimethyl carbonate(DMC)with ethanol.Combined characterization results of FT-IR,XRD and TG suggest that the ILs had been immobilized on molecular sieve MCM-22.The influences of reaction temperature,time,and the mass ratio of MCM-22-CPTES-MIL/Ca O have also been investigated in detail.The catalytic tests demonstrated that MCM-22-CPTES-MIL/Ca O could catalyze the transesterification of DMC and ethanol with high efficiency,superior to those results of the heterogeneous catalysts reported previously.
基金Supported by the National Natural Sciences Foundation of China(91434107,21506232)National Key Projects for Fundamental Research and Development of China(2016YFB0600903)
文摘A large number of surplus glycerol from the biodiesel production can be used as renewable feedstock to produce glycerol carbonate. In this paper, a series of guanidine-based ionic liquids were synthesized to catalyze the transesterification of glycerol and dimethyl carbonate. The tunable basicity and the anion–cation cooperative effect were responsible for the obtained results. The [TMG][TFE] showed the best activity turnover frequency(TOF)of 1754.0 h^(-1), glycerol(GL) conversion of 91.8%, glycerol carbonate(GC) selectivity of 95.5%) at 80 °C with 0.1 mol% catalyst for 30 min. The reaction mechanism of the transesterification was also proposed.
基金supported by the National Key Research and Development Program of China(2022YFB4101800)National Natural Science Foundation of China(22278077,22108040)+2 种基金Key Program of Qingyuan Innovation Laboratory(00221004)Research Program of Qingyuan Innovation Laboratory(00523006)Natural Science Foundation of Fujian Province(2022J02019)。
文摘Dimethyl carbonate(DMC)is a crucial chemical raw material widely used in organic synthesis,lithiumion battery electrolytes,and various other fields.The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol.However,the utilization of this catalyst presents several challenges during the process,including equipment corrosion,the generation of solid waste,susceptibility to deactivation,and complexities in separation and recovery.To address these limitations,a series of alkaline poly(ionic liquid)s,i.e.[DVBPIL][PHO],[DVCPIL][PHO],and[TBVPIL][PHO],with different crosslinking degrees and structures,were synthesized through the construction of cross-linked polymeric monomers and functionalization.These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics.Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC.It was discovered that the appropriate cross-linking degree and structure of the[DVCPIL][PHO]catalyst resulted in a DMC yield of up to 80.6%.Furthermore,this catalyst material exhibited good stability,maintaining its catalytic activity after repeated use five times without significant changes.The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.
基金Financial supports from the Fundamental Research Funds for the Central Universities (No.TD2010-1,YX2011-36,TD2011-11)the National Natural Science Foundation of China(No.31170556)+3 种基金Research Fund for the Doctoral Program of Higher Education of China(No.20100014120007)China Postdoctoral Science Foundation(No.20110490303)Beijing Forestry University Young Scientist Fund(No.BLX2009003)Major State Basic Research Development Program of China(973 Program,No.2010CB732204)
文摘In the present study,the transesterification of glycerol trioleate was carried out over a basic ionic liquid,1-butyl-3- methylimidazolium hydroxide（[Bmim]OH） and an 87.2%yield of methyl ester was achieved.The product was isolated through simple decantation from the biphasic system due to the immiscibility of[BmimJOH with ester.[Bmim]OH can be easily recovered and reused six times without dramatic decrease in ester yield.
基金supported by the National Natural Science Foundation of China(21773068)the National Key Research and Development Program of China(2017YFA0403102,2020YFA0710201)Shanghai Leading Academic Discipline Project(B409).
文摘The synthesis of dimethyl carbonate(DMC)via transesterification of ethylene carbonate(EC)and methanol(MeOH)was an environmental and practical strategy.Herein,poly(ionic liquid)s(PILs)with swelling abilities were synthesized by free radical copolymerization of N-vinylimidazolium ionic liquids,sodium 4-vinylbenzoate and cross-linker(1,8-triethylene glycoldiyl-3,3'-divinylimidazolium bromide([(EG)_(3)-DVIm]Br_(2)).The swelling abilities of PILs in various solvents were measured,and PILs could swell in methanol(MeOH).The swelling ability of PILs in MeOH could be modulated by changing the cross-linker content and chain length of 3-alkyl-substituents on imidazolium.The swollen state of PILs in MeOH presented a porous cross-linked network structure observed by the cryo-scanning electron microscope(cryo-SEM).The swelling PILs were used to catalyze the transesterification of ethylene carbonate(EC)and MeOH to prepare the DMC,and the catalytic activities was correlated with the swelling abilities of PILs.The PIL with 3-butyl-substituent and 2.5 mol%cross-linker(poly[VBIm-VBA-DVIm]-2.5%)had the highest swelling ratio(Q=12.4(g/g))in MeOH and EC mixed solvents and exhibited excellent catalytic activities,which was similar to corresponding homogeneous ionic liquid.Furthermore,the catalyst could be reused up to seven runs without any considerable loss of its initial activity.
基金the Ministry of Science and Technology of China(National Key Research and Development Program,No.2016YFA0602900)the National Natural Science Foundation of China(No.21672119)for financial support。
文摘In this work,the protic ionic liquid[DBUH][Im](1,8-diazabicyclo[5.4.0]-7-undeceniumimidazolide)was developed as an efficient catalyst for the transesterification of ethylene carbonate with methanol to produce dimethyl carbonate.At 70℃,up to 97%conversion of ethylene carbonate and 91%yield of dimethyl ca rbonate were obtained with 1 mol%[DBUH][Im](relative to ethylene carbonate)as catalyst in 2 h.Even at room temperature,the conversion of ethylene carbonate can reach 94%and the yield of dimethyl carbonate can approach 81%for 6 h.Catalytic mechanism investigation showed the high catalytic efficiency of this ionic liquid results from the synergistic activation effect,wherein the cation can activate ethylene carbonate and the anion can activate methanol through hydrogen bond formatio n.Although the reusability of the ionic liquid need to be further improved,high efficiency and comme rcial availability of[DBUH][Im]render it a promising catalyst for the preparation of dimethyl carbonate.
