The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template...The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template.The effects of various parameters,i.e.,H2O2/C=C molar ratio,oxidant concentration,amount of the catalyst,reaction temperature,and time,were systematically studied.Furthermore,response surface methodology(RSM)was used to optimize the conditions to maximize the yield of epoxy MO and to evaluate the significance and interplay of the factors affecting the epoxy MO production.The H2O2/C=C molar ratio and catalyst amount were the determining factors for MO epoxidation,wherein the maximum yield of epoxy MO reached 94.9%over HTS-1 under the optimal conditions.展开更多
The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry.Herein,we integrate enzymatic catalysis and electrocata...The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry.Herein,we integrate enzymatic catalysis and electrocatalysis to propose a new route for the chiral epoxidation of styrene and its derivatives.Chloroperoxidase(CPO)functionalized with 1-ethyl-3-methylimidazolium bromide(ILEMB)was loaded onto cobalt nitrogen-doped carbon nanotubes(CoN@CNT)to form a biohybrid(CPO-ILEMB/CoN@CNT).H_(2)O_(2)species were generated in situ through a two-electron oxygen reduction reaction(2e–ORR)at CoN@CNT to initiate the following enzymatic epoxidation of styrene by CPO.CoN@CNT had high electroactivity for the ORR to produce H_(2)O_(2)at a more positive potential,prohibiting the conversion of FeⅢ to FeⅡ in the heme of CPO to maintain enzymatic activity.Meanwhile,CoN@CNT could serve as an ideal carrier for the immobilization of CPO-ILEMB.Hence,the coimmobilization of CPO-ILEMB and CoN@CNT could facilitate the diffusion of intermediate H_(2)O_(2),which achieved 17 times higher efficiency than the equivalent amounts of free CPO-ILEMB in bulk solution for styrene epoxidation.Notably,an enhancement(~45%)of chiral selectivity for the epoxidation of styrene was achieved.展开更多
The search for polyoxometalate-based catalysts has long attracted interest.Being designable in structure,stable and effective,polyoxoniobate-based catalysts have an exciting prospect for industrial applications.This p...The search for polyoxometalate-based catalysts has long attracted interest.Being designable in structure,stable and effective,polyoxoniobate-based catalysts have an exciting prospect for industrial applications.This paper not only summarizes recent advances in classic polyoxoniobate-catalyzed reactions,including chemical warfare agents and organic dyes degradation,epoxidation reactions,photocatalytic hydrogen evolution and base-catalyzed reactions but also discusses some representative cases and the speculative mechanism related to structures.In addition,the current challenges and perspectives in the fabrication of more efficient and promising polyoxoniobate-based catalysts are also presented.展开更多
基金supported by the Evonik Industries AGthe Program for New Century Excellent Talents in University(NCET-04-0270)~~
文摘The epoxidation of methyl oleate(MO)was conducted in the presence of aqueous H2O2 as the oxidant and hierarchical TS-1(HTS-1)as the catalyst;the catalyst was synthesized using polyquaternium-6 as the mesopore template.The effects of various parameters,i.e.,H2O2/C=C molar ratio,oxidant concentration,amount of the catalyst,reaction temperature,and time,were systematically studied.Furthermore,response surface methodology(RSM)was used to optimize the conditions to maximize the yield of epoxy MO and to evaluate the significance and interplay of the factors affecting the epoxy MO production.The H2O2/C=C molar ratio and catalyst amount were the determining factors for MO epoxidation,wherein the maximum yield of epoxy MO reached 94.9%over HTS-1 under the optimal conditions.
基金supported by the National Natural Science Foundation of China(22273056)the Science and Technology Innovation Team of Shaanxi Province(2023-CX-TD-27)the Fundamental Research Funds for the Central Universities(GK202202001).
文摘The chiral epoxidation of styrene and its derivatives is an important transformation that has attracted considerable scientific interest in the chemical industry.Herein,we integrate enzymatic catalysis and electrocatalysis to propose a new route for the chiral epoxidation of styrene and its derivatives.Chloroperoxidase(CPO)functionalized with 1-ethyl-3-methylimidazolium bromide(ILEMB)was loaded onto cobalt nitrogen-doped carbon nanotubes(CoN@CNT)to form a biohybrid(CPO-ILEMB/CoN@CNT).H_(2)O_(2)species were generated in situ through a two-electron oxygen reduction reaction(2e–ORR)at CoN@CNT to initiate the following enzymatic epoxidation of styrene by CPO.CoN@CNT had high electroactivity for the ORR to produce H_(2)O_(2)at a more positive potential,prohibiting the conversion of FeⅢ to FeⅡ in the heme of CPO to maintain enzymatic activity.Meanwhile,CoN@CNT could serve as an ideal carrier for the immobilization of CPO-ILEMB.Hence,the coimmobilization of CPO-ILEMB and CoN@CNT could facilitate the diffusion of intermediate H_(2)O_(2),which achieved 17 times higher efficiency than the equivalent amounts of free CPO-ILEMB in bulk solution for styrene epoxidation.Notably,an enhancement(~45%)of chiral selectivity for the epoxidation of styrene was achieved.
基金financially supported by the National Natural Science Foundations of China (Grant Nos. 22171045, 21773029 and 21971039)the Natural Science Fund of Fujian Province (Grant No. 2017J01579)Projects from State Key Laboratory of Structural Chemistry of China
文摘The search for polyoxometalate-based catalysts has long attracted interest.Being designable in structure,stable and effective,polyoxoniobate-based catalysts have an exciting prospect for industrial applications.This paper not only summarizes recent advances in classic polyoxoniobate-catalyzed reactions,including chemical warfare agents and organic dyes degradation,epoxidation reactions,photocatalytic hydrogen evolution and base-catalyzed reactions but also discusses some representative cases and the speculative mechanism related to structures.In addition,the current challenges and perspectives in the fabrication of more efficient and promising polyoxoniobate-based catalysts are also presented.
