The kinetics of simultaneous transesterification and esterification with a carbon-based solid acid catalyst was studied.Two solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and...The kinetics of simultaneous transesterification and esterification with a carbon-based solid acid catalyst was studied.Two solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and petroleum asphalt.These catalysts were characterized on the basis of elemental analysis,acidity site concentration,the Brunauer-Emmett-Teller（BET）surface area and pore size.The kinetic parameters with the two catalysts were determined,and the reaction system can be described as a pseudo homogeneous catalyzed reaction.All the forward and reverse reactions follow second order kinetics.The calculated concentration values from the kinetic equations are in good agreement with experimental values.展开更多
Several imidazolium ionic liquid（IL）-supported sulfonic acids with different anions,[C_3SO_3Hmim]HSO_4,[C_3SO_3Hmim]BF_4, [C_3SO_3 Hmim]PF_6,and[C_3SO_3Hmim]CF_3SO_3,were synthesized and applied as catalysts for est...Several imidazolium ionic liquid（IL）-supported sulfonic acids with different anions,[C_3SO_3Hmim]HSO_4,[C_3SO_3Hmim]BF_4, [C_3SO_3 Hmim]PF_6,and[C_3SO_3Hmim]CF_3SO_3,were synthesized and applied as catalysts for esterification reaction of benzoic acid. The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO_4^- shows the best catalytic activity.Only when less[C_3SO_3Hmim]HSO_4（0.3 equiv.） applied,was the product obtained with high yield of 97%.Furthermore, the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.展开更多
This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with et...This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.展开更多
The comprehensive utilization of iso-citronelene can solve the problem of resource waste, which is conducive to environmental protection and green economic development. In this paper, based on the alkene-ester-alcohol...The comprehensive utilization of iso-citronelene can solve the problem of resource waste, which is conducive to environmental protection and green economic development. In this paper, based on the alkene-ester-alcohol synthesis route, through the design of a reasonable orthogonal test scheme, the production process of isocitronelene hydration esterification under acid environment was studied in detail, to explore the optimal process conditions. The results showed that the optimum process was as follows: iso-citronelene: organic acid = 1:2, catalyst was sulfuric acid, dosage was about 2%~5% of iso-citronelene, reaction time was 5 hours. Under the condition of iso-citronelene + acetic acid, the synthetic yield of the hydration esterification of iso-citronelene was over 85%, and the content of alcohol in the product was > 90%.展开更多
Esterification of acrylic acid（AA） to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorptio...Esterification of acrylic acid（AA） to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorption, TGA-DTA, XPS, and ammonia adsorption FTIR. The effects of Si/Al ratio, zirconium sulfate（ZS） loading on HZSM-5 and calcination temperature on the esterification were investigated. When 20% （mass fraction） ZS is loaded on HZSM-5, the conversion of AA reaches 100%. XRD analysis indicates that ZS is highly dispersed on HZSM-5 because no crystalline structure assigned to ZS is found. Catalytic activity and hydrophobicity of ZS supported on HZSM-5 are higher compared with those of parent ZS or HZSM-5. Results show that this kind of novel catalysts is an efficient water tolerant solid acid catalyst for esterification reactions.展开更多
A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron...A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions：crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.展开更多
A macromer, methoxypolyethylene glycol acrylate （MPEGAA）, was synthesized by direct esterification using methoxypolyethylene glycol （MPEG-1200） and acrylic acid （AA） as the main materials. MPEGAA was then used t...A macromer, methoxypolyethylene glycol acrylate （MPEGAA）, was synthesized by direct esterification using methoxypolyethylene glycol （MPEG-1200） and acrylic acid （AA） as the main materials. MPEGAA was then used to prepare a polyacrylic acid superplasticizer modified with 2-acrylamido-2- methylpropane sulfonic acid （AMPS）. A single-factor test was performed to investigate the effects of the molar ratio of acid to alcohol （n（AA）/n（MPEG））, inhibitor amount, catalyst amount, temperature, and time of esterification on the synthesis of MPEGAA. The experimental results showed that the optimal esterification conditions were as follows： n（AA）/n（MPEG）, 3.5：1; amount of hydroquinone （as an inhibitor）, 1.2%; amount of para-toluenesulfonic acid （as a catalyst）, 5.5%; reaction temperature, 95 ~C; and reaction time, 6 h. The AMPS- modified polyacrylic acid superplasticizer prepared under the optimal esterification conditions enabled the achievement and maintenance of high cement dispersibility. At an admixture amount of 0.15%, the cement paste fluidity was initially as high as 300 mm, and then decreased to 315 mm after 1 h and to 290 mm after 2 h.展开更多
Acetonylacetone 1 was treated with thiourea,aniline,glycine and glutamic acid to give pyrrole derivatives 2,3,5,and 9 by Paal-Knorr reaction,respectively.Then 3 was successfully transformed into the related pyrrole de...Acetonylacetone 1 was treated with thiourea,aniline,glycine and glutamic acid to give pyrrole derivatives 2,3,5,and 9 by Paal-Knorr reaction,respectively.Then 3 was successfully transformed into the related pyrrole derivative 4 by Mannich reaction. Compounds 6,7 and 8 were obtained by reacting 5 with phenethyl alcohol,phenylallylic alcohol and leaf alcohol by esterification reactions,respectively.The structures of all new products were elucidated by IR,NMR and HRMS spectra.展开更多
Isoconellone is an organic substance with irritating smell, which cannot be directly used and will cause physical discomfort when inhaled. Generally, the esterification-saponification method is adopted to make it into...Isoconellone is an organic substance with irritating smell, which cannot be directly used and will cause physical discomfort when inhaled. Generally, the esterification-saponification method is adopted to make it into ester or alcohol which can be directly applied to improve its utilization value. In this paper, through experimental research, a high-efficiency esterification treatment technology of rectification technology is proposed. The traditional esterification reaction is carried out in the rectification tower to improve the utilization rate of isoconellone. The experimental analysis shows that the yield of alcohols is 66.5% when the ratio of isoconellone to formic acid is 2: 3-1: 3, the theoretical plate number of the rectifying tower is 40-60, the reaction temperature is 85-90℃, the dosage of catalyst is 2-5% of the reactants, the saponification temperature is controlled at 70-100℃, and at the same time the concentration of by-products is reduced, the treatment pressure of three wastes is reduced, which is very friendly to the environment and has good economic benefits.展开更多
Nitrogen-rich zeolitic imidazolate frameworks(ZIFs)are ideal precursors for the synthesis of metal single atoms anchored on N-doped carbon.However,the microporous structures of conventional ZIFs lead to low mass trans...Nitrogen-rich zeolitic imidazolate frameworks(ZIFs)are ideal precursors for the synthesis of metal single atoms anchored on N-doped carbon.However,the microporous structures of conventional ZIFs lead to low mass transfer efficiency and low metal utilization of their derivatives.Here,we construct a composite of Co single atoms anchored on nitrogen-doped carbon with a three-dimensional ordered macroporous structure(Co-SA/3DOM-NC)by two-step pyrolysis of ordered macro/microporous ZnCo-ZIF.Co-SA/3DOM-NC shows high activity in the oxidative esterification of furfural,achieving a 99%yield of methyl 2-furoate under mild reaction conditions,which is significantly superior to the microporous and the Conanoparticle counterparts.The high activity of Co-SA/3DOM-NC should be attributed to the CoN4 centers with high intrinsic activity and the ordered macroporous structure,promoting the mass transfer of reactants and accessibility of active sites.展开更多
文摘The kinetics of simultaneous transesterification and esterification with a carbon-based solid acid catalyst was studied.Two solid acid catalysts were prepared by the sulfonation of carbonized vegetable oil asphalt and petroleum asphalt.These catalysts were characterized on the basis of elemental analysis,acidity site concentration,the Brunauer-Emmett-Teller（BET）surface area and pore size.The kinetic parameters with the two catalysts were determined,and the reaction system can be described as a pseudo homogeneous catalyzed reaction.All the forward and reverse reactions follow second order kinetics.The calculated concentration values from the kinetic equations are in good agreement with experimental values.
基金the National Natural Science Foundation of China(No.20676033)China Postdoctoral Science Foundation(No.20070410169)Shanghai Leading Academic Discipline Project(No.B507) for financial support
文摘Several imidazolium ionic liquid（IL）-supported sulfonic acids with different anions,[C_3SO_3Hmim]HSO_4,[C_3SO_3Hmim]BF_4, [C_3SO_3 Hmim]PF_6,and[C_3SO_3Hmim]CF_3SO_3,were synthesized and applied as catalysts for esterification reaction of benzoic acid. The experimental results indicate that imidazolium IL-supported sulfonic acid containing anion of HSO_4^- shows the best catalytic activity.Only when less[C_3SO_3Hmim]HSO_4（0.3 equiv.） applied,was the product obtained with high yield of 97%.Furthermore, the produced esters could be separated by decantation,and the catalyst could be reused after the removal of water.
文摘This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.
文摘The comprehensive utilization of iso-citronelene can solve the problem of resource waste, which is conducive to environmental protection and green economic development. In this paper, based on the alkene-ester-alcohol synthesis route, through the design of a reasonable orthogonal test scheme, the production process of isocitronelene hydration esterification under acid environment was studied in detail, to explore the optimal process conditions. The results showed that the optimum process was as follows: iso-citronelene: organic acid = 1:2, catalyst was sulfuric acid, dosage was about 2%~5% of iso-citronelene, reaction time was 5 hours. Under the condition of iso-citronelene + acetic acid, the synthetic yield of the hydration esterification of iso-citronelene was over 85%, and the content of alcohol in the product was > 90%.
基金Supported by the Research Fund for the Doctoral Program of Higher Education(No20050010014)the China Petroleum &Chemical Corporation ( No X503015 )the Key Discipline Construction Foundation of Beijing Education Committee ( NoXK100100643)
文摘Esterification of acrylic acid（AA） to produce AA esters has widespread application in the chemical industry. A series of water tolerant solid acid catalysts was prepared, and characterized by XRD, nitrogen adsorption, TGA-DTA, XPS, and ammonia adsorption FTIR. The effects of Si/Al ratio, zirconium sulfate（ZS） loading on HZSM-5 and calcination temperature on the esterification were investigated. When 20% （mass fraction） ZS is loaded on HZSM-5, the conversion of AA reaches 100%. XRD analysis indicates that ZS is highly dispersed on HZSM-5 because no crystalline structure assigned to ZS is found. Catalytic activity and hydrophobicity of ZS supported on HZSM-5 are higher compared with those of parent ZS or HZSM-5. Results show that this kind of novel catalysts is an efficient water tolerant solid acid catalyst for esterification reactions.
文摘A new solid acid catalyst,SO4^2-/TiO2 modified with tin,was prepared using a sol-gel method and its physicochemical properties were revealed by nitrogen adsorption-desorption,X-ray powder diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,infrared spectroscopy of adsorbed pyridine,temperature-programmed desorption of ammonia and thermal gravimetric analysis.The structure,acidity and thermal stability of the SO4^2-/TiO2-SnO2 catalyst were studied.Incorporating tin enlarged the specific surface area and decreased crystallite size of the SO4^2-/TiO2 catalyst.The total acid sites of the modified catalyst increased and Bronsted acid strength remarkably increased with increasing tin content.The decomposition temperature of sulfate radical in the modified catalyst was 100 ℃ greater and its mass loss was more than twice that of the SO4^2-/TiO2 catalyst.The SO4^2-/TiO2-SnO2 catalyst was designed to synthesize 1,6-hexanediol diacrylate by esterification of 1,6-hexanediol with crylic acid.The yield of 1,6-hexanediol diacrylate exceeded 87% under the optimal reaction conditions：crylic acid to 1,6-hexanediol molar ratio = 3.5,catalyst loading = 7%,reaction temperature = 130 ℃ and reaction time = 3 h.The modified catalyst exhibited excellent reusability and after 10 cycles the conversion of 1,6-hexanediol was above 81%.
基金Funded by the Fujian Education Department(Nos.JA11329,JA12412)the Quanzhou(Fujian)Technology Research and Development Program(No.2010G7)
文摘A macromer, methoxypolyethylene glycol acrylate （MPEGAA）, was synthesized by direct esterification using methoxypolyethylene glycol （MPEG-1200） and acrylic acid （AA） as the main materials. MPEGAA was then used to prepare a polyacrylic acid superplasticizer modified with 2-acrylamido-2- methylpropane sulfonic acid （AMPS）. A single-factor test was performed to investigate the effects of the molar ratio of acid to alcohol （n（AA）/n（MPEG））, inhibitor amount, catalyst amount, temperature, and time of esterification on the synthesis of MPEGAA. The experimental results showed that the optimal esterification conditions were as follows： n（AA）/n（MPEG）, 3.5：1; amount of hydroquinone （as an inhibitor）, 1.2%; amount of para-toluenesulfonic acid （as a catalyst）, 5.5%; reaction temperature, 95 ~C; and reaction time, 6 h. The AMPS- modified polyacrylic acid superplasticizer prepared under the optimal esterification conditions enabled the achievement and maintenance of high cement dispersibility. At an admixture amount of 0.15%, the cement paste fluidity was initially as high as 300 mm, and then decreased to 315 mm after 1 h and to 290 mm after 2 h.
基金the State Tobacco Monopoly Bureau(No.110200401014)Henan Province Office of Education of China(No.2008A208013)Technology Bureau of Zhengzhou(No.0910SGYN12302) support of this work
文摘Acetonylacetone 1 was treated with thiourea,aniline,glycine and glutamic acid to give pyrrole derivatives 2,3,5,and 9 by Paal-Knorr reaction,respectively.Then 3 was successfully transformed into the related pyrrole derivative 4 by Mannich reaction. Compounds 6,7 and 8 were obtained by reacting 5 with phenethyl alcohol,phenylallylic alcohol and leaf alcohol by esterification reactions,respectively.The structures of all new products were elucidated by IR,NMR and HRMS spectra.
文摘Isoconellone is an organic substance with irritating smell, which cannot be directly used and will cause physical discomfort when inhaled. Generally, the esterification-saponification method is adopted to make it into ester or alcohol which can be directly applied to improve its utilization value. In this paper, through experimental research, a high-efficiency esterification treatment technology of rectification technology is proposed. The traditional esterification reaction is carried out in the rectification tower to improve the utilization rate of isoconellone. The experimental analysis shows that the yield of alcohols is 66.5% when the ratio of isoconellone to formic acid is 2: 3-1: 3, the theoretical plate number of the rectifying tower is 40-60, the reaction temperature is 85-90℃, the dosage of catalyst is 2-5% of the reactants, the saponification temperature is controlled at 70-100℃, and at the same time the concentration of by-products is reduced, the treatment pressure of three wastes is reduced, which is very friendly to the environment and has good economic benefits.
基金supported by the National Natural Science Foundation of China(No.21825802,22138003,and 22108083)the Fundamental Research Funds for the Central Universities(No.2022ZYGXZR017 and 2022ZYGXZR108)+5 种基金the Foundation of Advanced Catalytic Engineering Research Center of the Ministry of Education(No.2020AC006)the State Key Laboratory of Pulp and Paper Engineering(No.2022C04 and 2022ZD05)the Guangdong Pearl River Talents Program(No.2021ZT09Z109 and 2021QN02C8)the Natural Science Foundation of Guangdong Province(No.2017A030312005 and 2022A1515012575)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110413)the Science and Technology Program of Guangzhou(No.202201010118)。
文摘Nitrogen-rich zeolitic imidazolate frameworks(ZIFs)are ideal precursors for the synthesis of metal single atoms anchored on N-doped carbon.However,the microporous structures of conventional ZIFs lead to low mass transfer efficiency and low metal utilization of their derivatives.Here,we construct a composite of Co single atoms anchored on nitrogen-doped carbon with a three-dimensional ordered macroporous structure(Co-SA/3DOM-NC)by two-step pyrolysis of ordered macro/microporous ZnCo-ZIF.Co-SA/3DOM-NC shows high activity in the oxidative esterification of furfural,achieving a 99%yield of methyl 2-furoate under mild reaction conditions,which is significantly superior to the microporous and the Conanoparticle counterparts.The high activity of Co-SA/3DOM-NC should be attributed to the CoN4 centers with high intrinsic activity and the ordered macroporous structure,promoting the mass transfer of reactants and accessibility of active sites.
