The influence of barium addition to a Ni/Al2O3 catalyst on the reaction intermediates formed,the activity,resistance of the catalyst to coking,and properties of the coke formed after acetic acid steam reforming were i...The influence of barium addition to a Ni/Al2O3 catalyst on the reaction intermediates formed,the activity,resistance of the catalyst to coking,and properties of the coke formed after acetic acid steam reforming were investigated in this study.The results showed the drastic effects of barium addition on the physicochemical properties and performances of the catalyst.The solid-phase reaction between alumina and BaO formed BaAl2O4,which re-constructed the alumina structure,resulting in a decrease in the specific surface area and an increase in the resistance of metallic Ni to sintering.The addition of barium was also beneficial for enhancing the catalytic activity,resulting from the changed catalytic reaction network.The in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study of the acetic acid steam reforming indicated that barium could effectively suppress the accumulation of the reaction intermediates of carbonyl,formate,and C=C functional groups on the catalyst surface,attributed to its relatively high ability to cause the gasification of these species.In addition,coking was considerably more significant over the Ba-Ni/Al2O3 catalyst.Moreover,the Ba-Ni/Al2O3 catalyst was more stable than the Ni/Al2O3catalyst,owing to the distinct forms of coke formed (carbon nanotube form over the Ba-Ni/Al2O3 catalyst,and the amorphous form over the Ni/Al2O3 catalyst).展开更多
An improved two-step process for converting carbohydrate biomass to acetic acid under hydrothermal conditions is proposed. The first step consists of the production of lactic acid from carbohydrate biomass, and the se...An improved two-step process for converting carbohydrate biomass to acetic acid under hydrothermal conditions is proposed. The first step consists of the production of lactic acid from carbohydrate biomass, and the second step consists of conversion of the lactic acid obtained in the first step to acetic acid using CuO as an oxidant. The results indicated that CuO as an oxidant in the second step can significantly improve the production of high-purity acetic acid from lactic acid, and the maximum yield of acetic acid was 61%, with a purity of 90%. The yield of acetic acid obtained using the improved two-step hydrothermal process from carbohydrate biomass, such as glucose, cellulose and starch, was greater than that obtained using traditional two-step process with H2O2 orO2. In addition, a proposed pathway for the production of acetic acid from lactic acid in the second step with CuO was also discussed. The present study provides a useful two-step process for the production of acetic acid from carbohydrate biomass.展开更多
The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, ...The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol^(-1) and the reaction heat being 10.06 kJ·mol^(-1). The dominant product predicted theoretically is in agreement with the experiment results.展开更多
A novel coordination polymer, [Ni(mal)(1,10′-phen)(H2O)]n(1)(mal=malate, 1,10′-phen=1,10-phenanthroline) was synthesized using malic acid which was generated from maleic acid via hydrothermal reaction. Complex 1, wh...A novel coordination polymer, [Ni(mal)(1,10′-phen)(H2O)]n(1)(mal=malate, 1,10′-phen=1,10-phenanthroline) was synthesized using malic acid which was generated from maleic acid via hydrothermal reaction. Complex 1, which displays a two-dimensional supramolecular network, was formed by the addition reaction of Ni and maleic acid with water molecules. To our knowledge, several coordination polymers have been directly synthesized from malic acid, but these types of complexes have seldom been synthesized from maleic acid via hydrothermal reactions. When Ni(Ⅱ) ion was changed to Zn(Ⅱ) ion under the same condition, two-dimensional covalent complex 2[Zn2(fma)2(1,10′-phen)2]n(fma=fumatic acid) was formed. Furthermore, complex 2 exhibits intense photoluminescent property at room temperature.展开更多
TiO2 nanotube precursor was synthesized by the hydrothermal reaction o f TiO2 powders with NaOH solution and the properties of the nanotube materials w ere tuned using different post-treatments. Transmission electron ...TiO2 nanotube precursor was synthesized by the hydrothermal reaction o f TiO2 powders with NaOH solution and the properties of the nanotube materials w ere tuned using different post-treatments. Transmission electron microscopic (TE M) observation revealed that the nanotube could be obtained by either a direct r inse with acid solution or rinse with distilled water followed by acid solution. The results of X-ray diffraction (XRD) and inductively coupled plasma (ICP) ana lysis indicated that the nanotube material was composed of H2Ti2O5·H2O. In addi tion, the photocatalytic activities of the resulting catalysts were found to be strongly dependent on the post-treatment. The results of the photocatalytic reac tion showed that the degradation of Acid-red 3B dye fitted pseudo-zero-order kin etics and TiO2 nanotube prepared under direct rinse with acid solution exhibited a higher catalytic efficiency compared to other catalysts.展开更多
A new one-dimensional (1-D) compound [Sm(PCA)3(H2O)2]n·6nH2O (1, HPCA=pyrazinecarboxylic acid) has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Co...A new one-dimensional (1-D) compound [Sm(PCA)3(H2O)2]n·6nH2O (1, HPCA=pyrazinecarboxylic acid) has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the Pbca space group of orthorhombic system with a=19.465(3), b=12.034(4), c=19.842(4) , V=4648(2)3, C15H25N6O14Sm, Mr=663.76, Dc=1.897 g/cm3, S=1.023, μ(MoKα)=2.610 mm-1, F(000)=2648, R=0.0239 and wR=0.0616. Compound 1 is characteristic of an infinite 1-D chain-like structure with the samarium atoms locating at an environment of a monocapped square antiprism. The [Sm(PCA)3(H2O)2]n chains and the lattice water molecules interconnect together through π-π interactions and hydrogen bonding interactions to yield a 3-D supramolecular framework. Photoluminescent investigation reveals that the title compound displays an emission in the greenish blue region.展开更多
N,N0-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.
A hydrothermal reaction of 1,3,5-benzene-tricarboxylic acid (H3BTC) with cad- mium acetate, zinc acetate and pyridine led to the formation of pink crystals of [Cd2Zn(BTC)2- (H2O)4]n?2nH2O 1. Single-crystal X-ray diffr...A hydrothermal reaction of 1,3,5-benzene-tricarboxylic acid (H3BTC) with cad- mium acetate, zinc acetate and pyridine led to the formation of pink crystals of [Cd2Zn(BTC)2- (H2O)4]n?2nH2O 1. Single-crystal X-ray diffraction analysis has revealed that 1 (Cd2ZnC18H18O18) crystallizes in the monoclinic system, space group C2/c with a = 19.4328(7), b = 7.1420(3), c = 18.0426(5) ?, β = 118.035(1)o, V = 2210.3(1) ?3, Mr = 812.49, Dc = 2.442 g/cm3, Z = 4, μ(MoKα) = 3.081 mm-1 and F(000) =1584. A total of 10735 reflections were collected, of which 2544 were unique. The structure was refined to R = 0.0200 and wR = 0.0603 for 2388 observed reflections with I>2σ(I). The crystal structure consists of cadmium(II)/zinc(II) carboxylates of BTC as well as coordination and discrete water molecules. Extension of the coordination geometry around three metal centers (Cd(1), Cd(2) and Zn(1)), two BTC3- ligands and four coordinated water molecules generates a three-dimensional coordination polymer.展开更多
基金supported by the National Natural Science Foundation of China(No.51876080)the Strategic International Scientific and Technological Innovation Cooperation Special Funds of National Key Research and Development Program of China(No.2016YFE0204000)+3 种基金the Program for Taishan Scholars of Shandong Province Governmentthe Recruitment Program of Global Experts(Thousand Youth Talents Plan)the Natural Science Foundation of Shandong Province(ZR2017BB002)the Key Research and Development Program of Shandong Province(2018GSF116014)。
文摘The influence of barium addition to a Ni/Al2O3 catalyst on the reaction intermediates formed,the activity,resistance of the catalyst to coking,and properties of the coke formed after acetic acid steam reforming were investigated in this study.The results showed the drastic effects of barium addition on the physicochemical properties and performances of the catalyst.The solid-phase reaction between alumina and BaO formed BaAl2O4,which re-constructed the alumina structure,resulting in a decrease in the specific surface area and an increase in the resistance of metallic Ni to sintering.The addition of barium was also beneficial for enhancing the catalytic activity,resulting from the changed catalytic reaction network.The in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) study of the acetic acid steam reforming indicated that barium could effectively suppress the accumulation of the reaction intermediates of carbonyl,formate,and C=C functional groups on the catalyst surface,attributed to its relatively high ability to cause the gasification of these species.In addition,coking was considerably more significant over the Ba-Ni/Al2O3 catalyst.Moreover,the Ba-Ni/Al2O3 catalyst was more stable than the Ni/Al2O3catalyst,owing to the distinct forms of coke formed (carbon nanotube form over the Ba-Ni/Al2O3 catalyst,and the amorphous form over the Ni/Al2O3 catalyst).
基金supported by the National Natural Science Foundation of China(No.21277091)the State Key Program of National Natural Science Foundation of China(No.21436007)+2 种基金key Basic Research Projects of Science and Technology Commission of Shanghai(14JC1403100)the Program for Professor of Special Appointment(Eastern Scholar) at Shanghai Institutions of Higher Learning(ZXDF160002)the Project-sponsored by SRF for ROCS,SEM(BG1600002)
文摘An improved two-step process for converting carbohydrate biomass to acetic acid under hydrothermal conditions is proposed. The first step consists of the production of lactic acid from carbohydrate biomass, and the second step consists of conversion of the lactic acid obtained in the first step to acetic acid using CuO as an oxidant. The results indicated that CuO as an oxidant in the second step can significantly improve the production of high-purity acetic acid from lactic acid, and the maximum yield of acetic acid was 61%, with a purity of 90%. The yield of acetic acid obtained using the improved two-step hydrothermal process from carbohydrate biomass, such as glucose, cellulose and starch, was greater than that obtained using traditional two-step process with H2O2 orO2. In addition, a proposed pathway for the production of acetic acid from lactic acid in the second step with CuO was also discussed. The present study provides a useful two-step process for the production of acetic acid from carbohydrate biomass.
基金Supported by the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1601215)the Ministry of Education "Chunhui Plan"(Z2016177)
文摘The reaction mechanism of o-aminophenol, acetic acid and phosphorus oxytrichloride in one-pot to form 2-methyl benzoxazole was studied by density functional theory. The geometries of the reactants, transition states, intermediates and products were optimized at the GGA/PW91/DNP level. Vibration analysis was carried out to confirm the transition state structure. Two possible reaction pathways were investigated in this study. The result indicates that the reaction Re→TS1→IM1→TSA2→IMA2→TSA3→IMA3→TSA4→IMA4→TSA5→P2 is the main pathway, the activation energy of which is the lowest. Re→TS1→IM1 is the rate-limiting step, with the activation energy being 221.54 kJ·mol^(-1) and the reaction heat being 10.06 kJ·mol^(-1). The dominant product predicted theoretically is in agreement with the experiment results.
基金Supported by the National Natural Science Foundation of China(No20371011)
文摘A novel coordination polymer, [Ni(mal)(1,10′-phen)(H2O)]n(1)(mal=malate, 1,10′-phen=1,10-phenanthroline) was synthesized using malic acid which was generated from maleic acid via hydrothermal reaction. Complex 1, which displays a two-dimensional supramolecular network, was formed by the addition reaction of Ni and maleic acid with water molecules. To our knowledge, several coordination polymers have been directly synthesized from malic acid, but these types of complexes have seldom been synthesized from maleic acid via hydrothermal reactions. When Ni(Ⅱ) ion was changed to Zn(Ⅱ) ion under the same condition, two-dimensional covalent complex 2[Zn2(fma)2(1,10′-phen)2]n(fma=fumatic acid) was formed. Furthermore, complex 2 exhibits intense photoluminescent property at room temperature.
文摘TiO2 nanotube precursor was synthesized by the hydrothermal reaction o f TiO2 powders with NaOH solution and the properties of the nanotube materials w ere tuned using different post-treatments. Transmission electron microscopic (TE M) observation revealed that the nanotube could be obtained by either a direct r inse with acid solution or rinse with distilled water followed by acid solution. The results of X-ray diffraction (XRD) and inductively coupled plasma (ICP) ana lysis indicated that the nanotube material was composed of H2Ti2O5·H2O. In addi tion, the photocatalytic activities of the resulting catalysts were found to be strongly dependent on the post-treatment. The results of the photocatalytic reac tion showed that the degradation of Acid-red 3B dye fitted pseudo-zero-order kin etics and TiO2 nanotube prepared under direct rinse with acid solution exhibited a higher catalytic efficiency compared to other catalysts.
基金the financial support of the NSF of Jiangxi Province (200007GQH1685, 2008GQH0001)
文摘A new one-dimensional (1-D) compound [Sm(PCA)3(H2O)2]n·6nH2O (1, HPCA=pyrazinecarboxylic acid) has been synthesized via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the Pbca space group of orthorhombic system with a=19.465(3), b=12.034(4), c=19.842(4) , V=4648(2)3, C15H25N6O14Sm, Mr=663.76, Dc=1.897 g/cm3, S=1.023, μ(MoKα)=2.610 mm-1, F(000)=2648, R=0.0239 and wR=0.0616. Compound 1 is characteristic of an infinite 1-D chain-like structure with the samarium atoms locating at an environment of a monocapped square antiprism. The [Sm(PCA)3(H2O)2]n chains and the lattice water molecules interconnect together through π-π interactions and hydrogen bonding interactions to yield a 3-D supramolecular framework. Photoluminescent investigation reveals that the title compound displays an emission in the greenish blue region.
文摘N,N0-Diarylhydrazines have been prepared via the reaction of N-Boc-aryl hydrazines with boronic acids mediated by copper acetate. This mild reaction condition tolerates the presence of a variety of functional groups.
基金This work was supported by the National Natural Science Foundation of China (20171012) and Natural Science Foundation of Fujian Province (E0110010)
文摘A hydrothermal reaction of 1,3,5-benzene-tricarboxylic acid (H3BTC) with cad- mium acetate, zinc acetate and pyridine led to the formation of pink crystals of [Cd2Zn(BTC)2- (H2O)4]n?2nH2O 1. Single-crystal X-ray diffraction analysis has revealed that 1 (Cd2ZnC18H18O18) crystallizes in the monoclinic system, space group C2/c with a = 19.4328(7), b = 7.1420(3), c = 18.0426(5) ?, β = 118.035(1)o, V = 2210.3(1) ?3, Mr = 812.49, Dc = 2.442 g/cm3, Z = 4, μ(MoKα) = 3.081 mm-1 and F(000) =1584. A total of 10735 reflections were collected, of which 2544 were unique. The structure was refined to R = 0.0200 and wR = 0.0603 for 2388 observed reflections with I>2σ(I). The crystal structure consists of cadmium(II)/zinc(II) carboxylates of BTC as well as coordination and discrete water molecules. Extension of the coordination geometry around three metal centers (Cd(1), Cd(2) and Zn(1)), two BTC3- ligands and four coordinated water molecules generates a three-dimensional coordination polymer.
