The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is...The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of methanol/water.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
文摘The epoxidation reaction of propylene and hydrogen peroxide with zeolite catalyst containing titaniumsilicalite (TS-1)has been studied, and the reaction in the mixed solvent of water/methanol has been discussed. It is shown that the selective of epoxidation propylene decreases while the selective of propylene glycol increases, when the water content increases in the mixed solvent of methanol/water.
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.
