The 2% cross-linked poly[styrene(iodosodiacetate)] reacted with diarylselenides and sodium azides to afford a simple and mild synthetis method of 1-azido-2- arylselenoalkanes.
The promoting effect of introducing Zn into nano-ZSM-5 zeolites by conventional impregnation method and isomorphous substitution on the performance of 1-hexene aromatization was investigated. The nano-ZSM-5 zeolite wa...The promoting effect of introducing Zn into nano-ZSM-5 zeolites by conventional impregnation method and isomorphous substitution on the performance of 1-hexene aromatization was investigated. The nano-ZSM-5 zeolite was synthesized by a seed-induced method without organic templates. The Zn-modified nano-ZSM-5 zeolite catalysts, xZ n/HNZ5 and y Zn/Al-HNZ5, were prepared by the conventional impregnation method and isomorphous substitution, respectively. The structure, chemical composition and acidity of the catalysts were characterized by XRD, XRF, N2 adsorption, SEM, NH3-TPD and Py-IR, while the catalytic properties were evaluated at 480 °C and a weight hourly space velocity(WHSV) of 2.0 h-1 in the aromatization procedure of 1-hexene. Compared with xZ n/HNZ5, y Zn/Al-HNZ5 exhibited smaller particles and higher dispersion of Zn species, which led to greater intergranular mesopore and homogeneous acidity distribution. Experimental results indicated that the synergy effect between the Brnsted and Lewis acid sites of the isomorphously substituted nano-ZSM-5 zeolites could significantly increase aromatics yield and improve catalytic stability in the 1-hexene aromatization.展开更多
Covalent triazine-based frameworks(CTFs) are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used f...Covalent triazine-based frameworks(CTFs) are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate(Ⅱ) in place of commonly used toxic cyanides.Then,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/g.Among the synthesized CTFs,CTF_(DCP) exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.展开更多
An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a...An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.展开更多
Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance...Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance of different ionic liquid catalysts for toluene chloromethylation was also studied. The reaction was found to proceed under mild conditions with excellent conversion (up to 90%) in the absence of Lewis acids. The ionic liquids could be recycled and reused without loss of their catalytic activities.展开更多
A new kinetic model for commercial unit of toluene disproportionation and C9-armatiocs transalkylation is developed based on the reported reaction scheme.A time based catalyst deactivation function taking weight hourl...A new kinetic model for commercial unit of toluene disproportionation and C9-armatiocs transalkylation is developed based on the reported reaction scheme.A time based catalyst deactivation function taking weight hourly space velocity(WHSV)into account is incorporated into the model,which reasonably accounts for the loss in activity because of coke deposition on the surface of catalyst during long-term operation.The kinetic parameters are benchmarked with several sets of balanced plant data and estimated by the differential variable metric optimiza- tion method.Sets of plant data at different operating conditions are applied to make sure validation of the model and the results show a good agreement between the model predictions and plant observations.The simulation analysis of key variables such as temperature and WHSV affecting process performance is discussed in detail,giv- ing the guidance to select suitable operating conditions.展开更多
An operando dual‐beam Fourier transform infrared (DB‐FTIR) spectrometer was successfully developed using a facile method. The DB‐FTIR spectrometer is suitable for the real‐time study of the dynamic surface process...An operando dual‐beam Fourier transform infrared (DB‐FTIR) spectrometer was successfully developed using a facile method. The DB‐FTIR spectrometer is suitable for the real‐time study of the dynamic surface processes involved in gas/solid heterogeneous catalysis under real reaction conditionsbecause it can simultaneously collect reference and sample spectra. The influence of gas‐phasemolecular vibration and heat irradiation at real reaction temperatures can therefore be eliminated.The DB‐FTIR spectrometer was successfully used to follow the transformation of isobutene over nano‐sized HZSM‐5 zeolite under real reaction conditions.展开更多
The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studie...The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studied, coupled with comparison of aromatization tendencies of olefins, paraffins and paraffins with different degrees of chain branching. Test results had shown that the lower the silicon/aluminum ratio in the ZRP zeolite, the higher the aromatization reactivity of aliphatic hydrocarbons. Modification of ZRP zeolite by zinc and its zinc content had apparent impact on the yield and distribution of aromatics. The aromatization tendency of olefins was apparently better than paraffins, while the aromatization tendency of monomethyl paraffins was better than that of straight-chain paraffins with the exception of dimethyl paraffins, which had worse aromatization tendency because of their steric hindrance.展开更多
The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independent reactions was...The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independent reactions was determined by means of atomic coefficient matrix method. Based on reaction thermodynamic and stoichiometric knowledge, the heat effect, Gibbs free energy change and equilibrium constant for each independent reaction was calculated for the specified conditions. Under these conditions, based on the initial and final composition data from LPG aromatization experiments, the actual extent of reaction for each independent reaction was determined. Furthermore, the global reaction heat and adiabatic temperature rise of LPG aromatization reaction system could be estimated. This work would provide a theoretical guidance for the design and scale-up of reactor for LPG aromatization process, as well as for the selection of proper operating conditions.展开更多
The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ )...The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and 1CP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol (2), 2-cyclohexen-l-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.展开更多
Removal of trace olefins from aromatic liquids had been investigated in the presence of various ionic liquids like 1-ethyl-3-methylimidazoliurn bromochloroaluminate (EMIMBr-AlCl3), 1-butyl-3-methylimidazolium bromoc...Removal of trace olefins from aromatic liquids had been investigated in the presence of various ionic liquids like 1-ethyl-3-methylimidazoliurn bromochloroaluminate (EMIMBr-AlCl3), 1-butyl-3-methylimidazolium bromochloroaluminate (BMIMBr-AlCl3), l-hexyl-3-methylimidazolium bromochloroaluminate (HMIMBr-AlCl3), and 1-octyl-3-methylimidazolium bromochloroaluminate (OMIMBr-A1C13). It was found that the longer the alkyl chain of ionic liquid cations was, the higher the olefins conversion would be. OMIMBr-AlCl3 (with 0.67 molar fraction of AlCl3) had an obvious performance on olefins removal. The influences of various reaction parameters such as the dosage of catalyst, the reaction temperature, and the reaction time on the reaction catalyzed by OMIMBr-AlCl3 were investigated. Under optimum reaction conditions, a higher than 99% conversion of olefins was achieved. The preliminary results revealed that the process could save time, consume less energy, separate products easier, and cause less pollution to the environment.展开更多
The solvent-free reactions of aromatic ketones and aldehydes in the presence of Zn-ZnCl2 were performed with the aid of high-speed vibration mill, Retsch MM200 mixer mill and Retsch RM100 mortar grinder to give pinaco...The solvent-free reactions of aromatic ketones and aldehydes in the presence of Zn-ZnCl2 were performed with the aid of high-speed vibration mill, Retsch MM200 mixer mill and Retsch RM100 mortar grinder to give pinacol coupling and reduction products in varying yields.展开更多
A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the ...A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeC13/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeC13/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeC13/SiO2 ex- hibited higher molar ratio of Lewis acid sites and Brtpnsted acid sites, which might be another reason for the in- crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2% conversion and 82.0% selectivity were obtained. Mean- while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.展开更多
In our synthetic studies toward huperzine A, a diastereoselective α'-alkylation of the α-amido-γ-methyl hexenone 4 was real- ized through a dianion intermediate which significantly enhanced the reactivity. Under t...In our synthetic studies toward huperzine A, a diastereoselective α'-alkylation of the α-amido-γ-methyl hexenone 4 was real- ized through a dianion intermediate which significantly enhanced the reactivity. Under the attempted Heck reaction conditions, an unexpected and unprecedented palladium-catalyzed intramolecular T-arylation of 3 was observed, which generated 18 with bicyclo[3.3, l]nonane framework in satisfactory yield.展开更多
文摘The 2% cross-linked poly[styrene(iodosodiacetate)] reacted with diarylselenides and sodium azides to afford a simple and mild synthetis method of 1-azido-2- arylselenoalkanes.
基金Project supported by the National Natural Science Foundation of China(Nos.21572137,21871187)the Key Program of Sichuan Science and Technology Project(No.2018GZ0312)~~
基金Project(21276067)supported by the National Natural Science Foundation of China
文摘The promoting effect of introducing Zn into nano-ZSM-5 zeolites by conventional impregnation method and isomorphous substitution on the performance of 1-hexene aromatization was investigated. The nano-ZSM-5 zeolite was synthesized by a seed-induced method without organic templates. The Zn-modified nano-ZSM-5 zeolite catalysts, xZ n/HNZ5 and y Zn/Al-HNZ5, were prepared by the conventional impregnation method and isomorphous substitution, respectively. The structure, chemical composition and acidity of the catalysts were characterized by XRD, XRF, N2 adsorption, SEM, NH3-TPD and Py-IR, while the catalytic properties were evaluated at 480 °C and a weight hourly space velocity(WHSV) of 2.0 h-1 in the aromatization procedure of 1-hexene. Compared with xZ n/HNZ5, y Zn/Al-HNZ5 exhibited smaller particles and higher dispersion of Zn species, which led to greater intergranular mesopore and homogeneous acidity distribution. Experimental results indicated that the synergy effect between the Brnsted and Lewis acid sites of the isomorphously substituted nano-ZSM-5 zeolites could significantly increase aromatics yield and improve catalytic stability in the 1-hexene aromatization.
基金supported by the National Natural Science Foundation of China(21373202,21525315)~~
文摘Covalent triazine-based frameworks(CTFs) are important microporous materials with a wide range of applications.Here,we demonstrate an environmentally benign and economic synthetic pathway to CTFs.The monomers used for CTFs,aromatic nitriles,were obtained by cyanation using nontoxic potassium hexacyanoferrate(Ⅱ) in place of commonly used toxic cyanides.Then,the CTFs were synthesized by trimerization of the corresponding cyano monomers in molten zinc chloride.A series of CTFs was synthesized,and the highest Brunauer-Emmett-Teller surface area measured in this series was 2404 m^2/g.Among the synthesized CTFs,CTF_(DCP) exhibited excellent CO_2 adsorption properties,with a CO_2 uptake of 225 mg/g at 0℃.
基金supported by the Intercollegiate Key Scientific Research Projects of Henan Province(15A150018)~~
文摘An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.
基金Supported by the National Natural Science Foundation of China (20376015), the Natural Science Foundation of Guangdong Province (32491) and Guangzhou Project of Science & Technology (2004J1-C0151).
文摘Ionic liquids have been used as catalysts for Blanc reaction of toluene. The effects of reaction temperature, reaction time and dosage of the ionic liquid catalyst have been investigated, and the catalytic performance of different ionic liquid catalysts for toluene chloromethylation was also studied. The reaction was found to proceed under mild conditions with excellent conversion (up to 90%) in the absence of Lewis acids. The ionic liquids could be recycled and reused without loss of their catalytic activities.
基金Supported by the National'Creative Research Groups Science Foundation of China (No.60421002) and priority supported financially by "the New Century 151 Talent Project" of Zhejiang Province.
文摘A new kinetic model for commercial unit of toluene disproportionation and C9-armatiocs transalkylation is developed based on the reported reaction scheme.A time based catalyst deactivation function taking weight hourly space velocity(WHSV)into account is incorporated into the model,which reasonably accounts for the loss in activity because of coke deposition on the surface of catalyst during long-term operation.The kinetic parameters are benchmarked with several sets of balanced plant data and estimated by the differential variable metric optimiza- tion method.Sets of plant data at different operating conditions are applied to make sure validation of the model and the results show a good agreement between the model predictions and plant observations.The simulation analysis of key variables such as temperature and WHSV affecting process performance is discussed in detail,giv- ing the guidance to select suitable operating conditions.
基金supported by the National Natural Science Foundation of China (21603023)the PetroChina Innovation Foundation, China (2014D-5006-0501)~~
文摘An operando dual‐beam Fourier transform infrared (DB‐FTIR) spectrometer was successfully developed using a facile method. The DB‐FTIR spectrometer is suitable for the real‐time study of the dynamic surface processes involved in gas/solid heterogeneous catalysis under real reaction conditionsbecause it can simultaneously collect reference and sample spectra. The influence of gas‐phasemolecular vibration and heat irradiation at real reaction temperatures can therefore be eliminated.The DB‐FTIR spectrometer was successfully used to follow the transformation of isobutene over nano‐sized HZSM‐5 zeolite under real reaction conditions.
文摘The performance of ZRP zeolite catalysts for aromatization of C6 aliphatic hydrocarbons was investigated in a pulsed microreactor. The influence of metal modified ZRP zeolites on aromatization reaction was also studied, coupled with comparison of aromatization tendencies of olefins, paraffins and paraffins with different degrees of chain branching. Test results had shown that the lower the silicon/aluminum ratio in the ZRP zeolite, the higher the aromatization reactivity of aliphatic hydrocarbons. Modification of ZRP zeolite by zinc and its zinc content had apparent impact on the yield and distribution of aromatics. The aromatization tendency of olefins was apparently better than paraffins, while the aromatization tendency of monomethyl paraffins was better than that of straight-chain paraffins with the exception of dimethyl paraffins, which had worse aromatization tendency because of their steric hindrance.
文摘The reaction heat effect analysis for the aromatization process of Liquefied Petroleum Gas (LPG) was completed in this paper. In order to characterize this complex reaction system, one set of independent reactions was determined by means of atomic coefficient matrix method. Based on reaction thermodynamic and stoichiometric knowledge, the heat effect, Gibbs free energy change and equilibrium constant for each independent reaction was calculated for the specified conditions. Under these conditions, based on the initial and final composition data from LPG aromatization experiments, the actual extent of reaction for each independent reaction was determined. Furthermore, the global reaction heat and adiabatic temperature rise of LPG aromatization reaction system could be estimated. This work would provide a theoretical guidance for the design and scale-up of reactor for LPG aromatization process, as well as for the selection of proper operating conditions.
文摘The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and 1CP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol (2), 2-cyclohexen-l-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.
文摘Removal of trace olefins from aromatic liquids had been investigated in the presence of various ionic liquids like 1-ethyl-3-methylimidazoliurn bromochloroaluminate (EMIMBr-AlCl3), 1-butyl-3-methylimidazolium bromochloroaluminate (BMIMBr-AlCl3), l-hexyl-3-methylimidazolium bromochloroaluminate (HMIMBr-AlCl3), and 1-octyl-3-methylimidazolium bromochloroaluminate (OMIMBr-A1C13). It was found that the longer the alkyl chain of ionic liquid cations was, the higher the olefins conversion would be. OMIMBr-AlCl3 (with 0.67 molar fraction of AlCl3) had an obvious performance on olefins removal. The influences of various reaction parameters such as the dosage of catalyst, the reaction temperature, and the reaction time on the reaction catalyzed by OMIMBr-AlCl3 were investigated. Under optimum reaction conditions, a higher than 99% conversion of olefins was achieved. The preliminary results revealed that the process could save time, consume less energy, separate products easier, and cause less pollution to the environment.
文摘The solvent-free reactions of aromatic ketones and aldehydes in the presence of Zn-ZnCl2 were performed with the aid of high-speed vibration mill, Retsch MM200 mixer mill and Retsch RM100 mortar grinder to give pinacol coupling and reduction products in varying yields.
基金Supported by the National Basic Research Program of China("973"Program,No.21476163)
文摘A series of metal chlorides supported solid catalysts were prepared by simple wet impregnation method. Their catalytic performances for Friedel-Crafts acylation of toluene with benzoyl chloride were evaluated and the excellent results were obtained over FeC13/SiO2. These catalysts were characterized by BET, NH3-TPD and FT-IR of pyridine adsorption to clarify the structure-activity relationship. It was found that FeC13/SiO2 has larger pore size and pore volume than other catalysts, which increased the accessibility of the catalyst. In addition, FeC13/SiO2 ex- hibited higher molar ratio of Lewis acid sites and Brtpnsted acid sites, which might be another reason for the in- crease of toluene conversion. Furthermore, the reaction parameters, including temperature, time and molar ratio, were optimized. Under the optimized conditions, 91.2% conversion and 82.0% selectivity were obtained. Mean- while, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. Finally, the catalyst was reused for four runs with slight loss in catalytic activity, which attributed to the drain of the active component.
基金supported by the National Natural Science Foundation of China (20902101 & 21172246)National Basic Research Program of China (973 Program) (2010CB833206)
文摘In our synthetic studies toward huperzine A, a diastereoselective α'-alkylation of the α-amido-γ-methyl hexenone 4 was real- ized through a dianion intermediate which significantly enhanced the reactivity. Under the attempted Heck reaction conditions, an unexpected and unprecedented palladium-catalyzed intramolecular T-arylation of 3 was observed, which generated 18 with bicyclo[3.3, l]nonane framework in satisfactory yield.