Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme ch...Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme challenges due to the susceptibility of the copper cathode in a reduction environment.Herein,a small molecule modulation electrodeposition strategy is introduced that regulates the structure of Cubased materials through modification with citric acid(CA)ligands,aiming for highly active and selective ECSH.The as-prepared EDCu-CA electrode achieves more than 97%alkyne conversion and 99%olefin selectivity.In-situ Raman and Auger electron spectroscopy(AES)data provide evidence that active Cu^(+)sites can stably exist in the EDCu-CA during the catalytic process.Density functional theory(DFT)calculations indicate that the modulation by CA contributes to maintaining Cu in a positive valence state,and Cu^(+)can inhibit the over-hydrogenation of olefins.Moreover,by utilizing a large-area electrode for longterm electrolysis,g-level conversion and a 92%separation yield of olefin can be achieved,demonstrating a viable application prospect.This study offers a promising route for designing Cu-based catalysts for the highly selective electrocata lytic conversion of organic substrates to value-added chemicals in water.展开更多
The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameter...The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameters, e.g. temperature, CO2 pressure, PEG molecular weight and loading on the reaction were carefully examined. Moreover, various substrates worked well in the presence of PEG 1000 under 5 MPa of CO2 and 2 MPa of O2 at 100 ℃ for 12 to 24 h and acceptable yield and selectivity could be obtained in most cases. Preliminary mechanistic investigations were also discussed.展开更多
The conversion of inexpensive,available C1 feedstock of carbon dioxide(CO_(2))into value-added fine chemicals via homogeneous or heterogeneous catalysis has attracted great recent interest.Coinagemetal-based(Cu,Ag,and...The conversion of inexpensive,available C1 feedstock of carbon dioxide(CO_(2))into value-added fine chemicals via homogeneous or heterogeneous catalysis has attracted great recent interest.Coinagemetal-based(Cu,Ag,and Au)catalysis has emerged as a synthetic strategy for a wide range of organic chemical reactions in past decades.In coinage-metal-catalyzed carboxylation,CO_(2)is adopted as a carboxylation reagent,while coinage-metal salts,complexes,and nanoparticles(NPs)serve as a Lewis acid catalyst to activate unsaturated chemicals,particularly alkynes.This mini-review focuses on the recent advances of coinage-metal-catalyzed carboxylation of terminal alkynes with CO_(2).Other respects,such as the role of bases,the influence of trace water,and solvent effects are also highlighted.展开更多
基金financially supported by the National Natural Science Foundation of China(NSFC)(22179056,22172018)the Liaoning Revitalization Talents Program(XLYC2002097,1807210)+2 种基金the Key Projects of Liaoning Provincial Education Department(JYTZD2023001)the Fundamental Research Funds for the Central Universities(DUT23LAB611)Yingkou Talents Program。
文摘Selective electrocatalytic semi-hydrogenation(ECSH)of alkynes in water using Cu catalysts is highly relevant for the production of value-added chemicals.However,achieving high olefin selectivity still poses extreme challenges due to the susceptibility of the copper cathode in a reduction environment.Herein,a small molecule modulation electrodeposition strategy is introduced that regulates the structure of Cubased materials through modification with citric acid(CA)ligands,aiming for highly active and selective ECSH.The as-prepared EDCu-CA electrode achieves more than 97%alkyne conversion and 99%olefin selectivity.In-situ Raman and Auger electron spectroscopy(AES)data provide evidence that active Cu^(+)sites can stably exist in the EDCu-CA during the catalytic process.Density functional theory(DFT)calculations indicate that the modulation by CA contributes to maintaining Cu in a positive valence state,and Cu^(+)can inhibit the over-hydrogenation of olefins.Moreover,by utilizing a large-area electrode for longterm electrolysis,g-level conversion and a 92%separation yield of olefin can be achieved,demonstrating a viable application prospect.This study offers a promising route for designing Cu-based catalysts for the highly selective electrocata lytic conversion of organic substrates to value-added chemicals in water.
基金supported by the National Natural Science Foundation of China(No.21172125)the Ministry of Science and Technology (2012BAD32B10)+1 种基金the "111" Project of Ministry of Education of China(Project No.B06005)the Committee of Science and Technology of Tianjin
文摘The selective aerobic oxidation of alkynes to corresponding α,β-acetylenic ketones was achieved in polyethylene glycol/dense CO2/O2 biphasic system without any catalyst or additive. The effects of reaction parameters, e.g. temperature, CO2 pressure, PEG molecular weight and loading on the reaction were carefully examined. Moreover, various substrates worked well in the presence of PEG 1000 under 5 MPa of CO2 and 2 MPa of O2 at 100 ℃ for 12 to 24 h and acceptable yield and selectivity could be obtained in most cases. Preliminary mechanistic investigations were also discussed.
文摘The conversion of inexpensive,available C1 feedstock of carbon dioxide(CO_(2))into value-added fine chemicals via homogeneous or heterogeneous catalysis has attracted great recent interest.Coinagemetal-based(Cu,Ag,and Au)catalysis has emerged as a synthetic strategy for a wide range of organic chemical reactions in past decades.In coinage-metal-catalyzed carboxylation,CO_(2)is adopted as a carboxylation reagent,while coinage-metal salts,complexes,and nanoparticles(NPs)serve as a Lewis acid catalyst to activate unsaturated chemicals,particularly alkynes.This mini-review focuses on the recent advances of coinage-metal-catalyzed carboxylation of terminal alkynes with CO_(2).Other respects,such as the role of bases,the influence of trace water,and solvent effects are also highlighted.
