The polysterene supported triphase transfer catalysts PS CH 2PPh 3I and PS CH 2(OCH 2CH 2) 4PPh 3I,with polyethoxyl chain and quaternary phosphine salt double funtions,were synthesized.The optimunconditions of synthes...The polysterene supported triphase transfer catalysts PS CH 2PPh 3I and PS CH 2(OCH 2CH 2) 4PPh 3I,with polyethoxyl chain and quaternary phosphine salt double funtions,were synthesized.The optimunconditions of synthesis were found.It was applicable to different reactions and their catalyst activities were studied,by the way.展开更多
A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.5...A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.55（H20）0.45 （3, PP = piperazine）, and Er（btc）（DABCO）0.15（H2O）0.85 （4, DABCO = 1,4- diazabicyclo[2.2.2]octane）, by grafting three different diamines onto the coordinatively unsaturated Er（III） ions into the channels of the desolvated lanthanide metal-organic framework （Er（otc））. The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4- for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests.展开更多
Inorganic-organic hybrid materials are promising for application in the field of photocatalysis because of their excellent properties.Therefore,their syntheses,mechanisms,and applications are reviewed in this paper.Fi...Inorganic-organic hybrid materials are promising for application in the field of photocatalysis because of their excellent properties.Therefore,their syntheses,mechanisms,and applications are reviewed in this paper.First,we introduce the role of inorganic-organic photocatalysts,their advantages and disadvantages,and their design principles.Second,we present the top-down and bottom-up synthesis methods of the hybrid materials.The interaction between inorganic and organic components in hybrid materials is discussed,followed by how to improve inorganic-organic photocatalysts.Third,the applications of hybrid materials in the field of photocatalysis,such as realizing hydrogen evolution,organic pollutant degradation,heavy metals and CO_(2) reduction,sterilization,and nitrogen fixation,are examined.Finally,the application prospects and development directions of inorganic-organic hybrid materials are explored and the unsolved problems are described.展开更多
Vitamin A ester was synthesized in organic solvents with immobilized lipase from Candida sp. The types of lipases, influences of solvent, the molar ratio of substrates, the reaction temperature and the water activity ...Vitamin A ester was synthesized in organic solvents with immobilized lipase from Candida sp. The types of lipases, influences of solvent, the molar ratio of substrates, the reaction temperature and the water activity in the reaction were studied in detail in order to obtain the optimum conditions for Vitamin A palmitate synthesis. In a system of hexane, 100mg immobilized Candida sp. lipase was used in the presence of 1.2mmol vitamin A acetate and 3.6mmol palmitic acid. The yield of vitamin A palmitate reached 81% in 12h at 25℃. The immobilized Candida sp. lipase was prepared by adsorbing Cand/da sp. fermentation broth on pretreated textile and could be reused for at least six batches.展开更多
It is a very fine substitutable energy technology to synthesize ethanol from biomass-derived syngas. This paper summarized the development of preparing ethanol from syngas, and especially elaborated on the research st...It is a very fine substitutable energy technology to synthesize ethanol from biomass-derived syngas. This paper summarized the development of preparing ethanol from syngas, and especially elaborated on the research status of catalysts for the process. Based on the relative researches on the reaction mechanism, structure and performance of the catalysts, the optimum design of catalysts with high activity was presented in this review, which set the theoretical and application foundation for the industrial production of ethanol from syngas.展开更多
29Si-NMR and 1H-NMR were used to follow up the basic hydrolysis of tetraethyl orthosilicate （TOES） and the results showed that species of monomer, dimer, trimer, cyclic and polymer silicates were formed. The monomer...29Si-NMR and 1H-NMR were used to follow up the basic hydrolysis of tetraethyl orthosilicate （TOES） and the results showed that species of monomer, dimer, trimer, cyclic and polymer silicates were formed. The monomer and dimer were favorable for the high activity of zeolite. XRD, 13C CP/MAS and 29Si NMR were used to trace the crystallization process of hollow titanium silicalite zeolites （HTS）. The results showed that the induction period of HTS was 80 min, and subsequently it took next 10 min to form HTS and the remaining time of the crystallization period might function for cleaning up the pores and/or washing off the impurities from the HTS zeolite. The catalytic oxidation performance of HTS zeolite is different from that of the acid activity of zeolite in which the conventional definition of crystallinity does not reflect the catalytic oxidation activity proportionally. The synthesized HTS samples were character- ized by XRD, FT-IR, UV-Vis and Raman spectra. It was confirmed that Ti was incorporated into the zeolite framework. The synthesized HTS samples revealed good repeatability and high activity for oxidation of phenol into diphenol.展开更多
Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical...Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical redox agents. Indirect electrolysis employing a redox catalyst has received tremendous attention, since it provides various advantages compared to direct electrolysis. With indirect electrolysis, overpotential of electron transfer can be avoided, which is inherently milder, thus wide functional group tolerance can be achieved. Additionally, chemoselectivity, regioselectivity, and stereoselectivity can be tuned by the redox catalysts used in indirect electrolysis. Furthermore, electrode passivation can be avoided by preventing the formation of polymer films on the electrode surface. Common redox catalysts include N-oxyl radicals, hypervalent iodine species, halides, amines, benzoquinones(such as DDQ and tetrachlorobenzoquinone), and transition metals. In recent years, great progress has been made in the field of indirect organic electrosynthesis using transition metals as redox catalysts for reaction classes including C–H functionalization, radical cyclization, and cross-coupling of aryl halides-each owing to the diverse reactivity and accessible oxidation states of transition metals. Although various reviews of organic electrosynthesis are available, there is a lack of articles that focus on recent research progress in the area of indirect electrolysis using transition metals, which is the impetus for this review.展开更多
Several transition metal oxides,including α-Fe2O3,Fe3O4,Co3O4,NiO,CuO and ZnO,were synthesized via an easily controlled hydrothermal method at assistance of organic amine(cyclohexylamine or triethylamine).The synthes...Several transition metal oxides,including α-Fe2O3,Fe3O4,Co3O4,NiO,CuO and ZnO,were synthesized via an easily controlled hydrothermal method at assistance of organic amine(cyclohexylamine or triethylamine).The synthesized samples were identified and characterized by X-ray diffraction(XRD),Transmission Electron Microscopy(TEM),High-resolution Electron Microscopy(HR-TEM),Field Emission Scanning Electron Microscopy(FE-SEM),N2 adsorption/desorption measurement.The resultant metal oxides displayed various morphologies in shape.The as-prepared samples were used as electrocatalysts(CuO was excluded) modified on a glassy carbon electrode for p-nitrophenol reduction in a basic solution.Fe3O4 and Co3O4 samples showed higher catalytic activities.展开更多
文摘The polysterene supported triphase transfer catalysts PS CH 2PPh 3I and PS CH 2(OCH 2CH 2) 4PPh 3I,with polyethoxyl chain and quaternary phosphine salt double funtions,were synthesized.The optimunconditions of synthesis were found.It was applicable to different reactions and their catalyst activities were studied,by the way.
基金supported by the National Natural Science Foundation of China(21372087)~~
文摘A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.55（H20）0.45 （3, PP = piperazine）, and Er（btc）（DABCO）0.15（H2O）0.85 （4, DABCO = 1,4- diazabicyclo[2.2.2]octane）, by grafting three different diamines onto the coordinatively unsaturated Er（III） ions into the channels of the desolvated lanthanide metal-organic framework （Er（otc））. The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4- for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests.
文摘Inorganic-organic hybrid materials are promising for application in the field of photocatalysis because of their excellent properties.Therefore,their syntheses,mechanisms,and applications are reviewed in this paper.First,we introduce the role of inorganic-organic photocatalysts,their advantages and disadvantages,and their design principles.Second,we present the top-down and bottom-up synthesis methods of the hybrid materials.The interaction between inorganic and organic components in hybrid materials is discussed,followed by how to improve inorganic-organic photocatalysts.Third,the applications of hybrid materials in the field of photocatalysis,such as realizing hydrogen evolution,organic pollutant degradation,heavy metals and CO_(2) reduction,sterilization,and nitrogen fixation,are examined.Finally,the application prospects and development directions of inorganic-organic hybrid materials are explored and the unsolved problems are described.
基金Supported by the National Natural Science Foundation of China (No.20325622), Key Technology R&D Programme (No.2001BA708B03-08) and 863 Hi-Technology Research and Development Program of China (No. 2002AA514030).
文摘Vitamin A ester was synthesized in organic solvents with immobilized lipase from Candida sp. The types of lipases, influences of solvent, the molar ratio of substrates, the reaction temperature and the water activity in the reaction were studied in detail in order to obtain the optimum conditions for Vitamin A palmitate synthesis. In a system of hexane, 100mg immobilized Candida sp. lipase was used in the presence of 1.2mmol vitamin A acetate and 3.6mmol palmitic acid. The yield of vitamin A palmitate reached 81% in 12h at 25℃. The immobilized Candida sp. lipase was prepared by adsorbing Cand/da sp. fermentation broth on pretreated textile and could be reused for at least six batches.
基金Project (No. 06GG2209052) supported by the Natural Science Foundation of Shandong Province, China
文摘It is a very fine substitutable energy technology to synthesize ethanol from biomass-derived syngas. This paper summarized the development of preparing ethanol from syngas, and especially elaborated on the research status of catalysts for the process. Based on the relative researches on the reaction mechanism, structure and performance of the catalysts, the optimum design of catalysts with high activity was presented in this review, which set the theoretical and application foundation for the industrial production of ethanol from syngas.
基金Project supported by the National Science Foundation of China(2006CB202508)
文摘29Si-NMR and 1H-NMR were used to follow up the basic hydrolysis of tetraethyl orthosilicate （TOES） and the results showed that species of monomer, dimer, trimer, cyclic and polymer silicates were formed. The monomer and dimer were favorable for the high activity of zeolite. XRD, 13C CP/MAS and 29Si NMR were used to trace the crystallization process of hollow titanium silicalite zeolites （HTS）. The results showed that the induction period of HTS was 80 min, and subsequently it took next 10 min to form HTS and the remaining time of the crystallization period might function for cleaning up the pores and/or washing off the impurities from the HTS zeolite. The catalytic oxidation performance of HTS zeolite is different from that of the acid activity of zeolite in which the conventional definition of crystallinity does not reflect the catalytic oxidation activity proportionally. The synthesized HTS samples were character- ized by XRD, FT-IR, UV-Vis and Raman spectra. It was confirmed that Ti was incorporated into the zeolite framework. The synthesized HTS samples revealed good repeatability and high activity for oxidation of phenol into diphenol.
基金supported by the National Natural Science Foundation of China (21821002, 21772222, and 91956112)Chinese Academy of Sciences (XDB20000000)Science and Technology Commission of Shanghai Municipality (18JC1415600 and 20JC1417100)。
文摘Organic electrosynthesis has been widely used as an environmentally conscious alternative to conventional methods for redox reactions because it utilizes electric current as a traceless redox agent instead of chemical redox agents. Indirect electrolysis employing a redox catalyst has received tremendous attention, since it provides various advantages compared to direct electrolysis. With indirect electrolysis, overpotential of electron transfer can be avoided, which is inherently milder, thus wide functional group tolerance can be achieved. Additionally, chemoselectivity, regioselectivity, and stereoselectivity can be tuned by the redox catalysts used in indirect electrolysis. Furthermore, electrode passivation can be avoided by preventing the formation of polymer films on the electrode surface. Common redox catalysts include N-oxyl radicals, hypervalent iodine species, halides, amines, benzoquinones(such as DDQ and tetrachlorobenzoquinone), and transition metals. In recent years, great progress has been made in the field of indirect organic electrosynthesis using transition metals as redox catalysts for reaction classes including C–H functionalization, radical cyclization, and cross-coupling of aryl halides-each owing to the diverse reactivity and accessible oxidation states of transition metals. Although various reviews of organic electrosynthesis are available, there is a lack of articles that focus on recent research progress in the area of indirect electrolysis using transition metals, which is the impetus for this review.
基金supported by the Excellent Young Academic Foundation of Anhui Province (2010SQRL163)
文摘Several transition metal oxides,including α-Fe2O3,Fe3O4,Co3O4,NiO,CuO and ZnO,were synthesized via an easily controlled hydrothermal method at assistance of organic amine(cyclohexylamine or triethylamine).The synthesized samples were identified and characterized by X-ray diffraction(XRD),Transmission Electron Microscopy(TEM),High-resolution Electron Microscopy(HR-TEM),Field Emission Scanning Electron Microscopy(FE-SEM),N2 adsorption/desorption measurement.The resultant metal oxides displayed various morphologies in shape.The as-prepared samples were used as electrocatalysts(CuO was excluded) modified on a glassy carbon electrode for p-nitrophenol reduction in a basic solution.Fe3O4 and Co3O4 samples showed higher catalytic activities.
