The cycloaddition of epoxides and carbon dioxide represents a straightforward and atom-efficient method for synthesis of cyclic carbonates and utilization of CO2. So far, homogeneous metal complexes have been mainly a...The cycloaddition of epoxides and carbon dioxide represents a straightforward and atom-efficient method for synthesis of cyclic carbonates and utilization of CO2. So far, homogeneous metal complexes have been mainly applied for such transformations. Here, we describe the synthesis of novel heterogeneous Zn-based catalysts, which were conveniently prepared by pyrolysis of an active- carbon-supported phenanthroline-ligated Zn(OAc)2 complex. Detail structural characterizations proved the existence of single zinc sites in the active material. Compared to a Zn-based nanoparticle (Zn-NP) catalyst, the resulting single metal atom catalyst (SAC) displayed improved activity and stability for the cycloaddition of epoxides. By applying the optimal catalyst, a variety of carbonates were successfully obtained in high yields with good functional group tolerance.展开更多
This study reports the development of a novel amino‐functionalized ionic liquid catalyst,namely 1‐butyl‐3‐methylimidazolium amino triazole([EMIM]ATZ),for the efficient and sustainable synthesis of ethyl methyl car...This study reports the development of a novel amino‐functionalized ionic liquid catalyst,namely 1‐butyl‐3‐methylimidazolium amino triazole([EMIM]ATZ),for the efficient and sustainable synthesis of ethyl methyl carbonate(EMC)via transesterification of dimethyl carbonate(DMC)and ethanol(C_(2)H_(5)OH)at room temperature.Addressing the limitations of conventional catalytic systems that require elevated temperatures(>75℃),[EMIM]ATZ achieves 62%DMC conversion and 56%EMC yield within 8 h under room temperature(25℃),while conventional ionic liquids([EMIM]Cl,[EMIM]BF_(4),[EMIM]PF_(6) etc.)showed almost no activity at room temperature.The catalyst's superior activity stems from its strong basicity(pH≈9.2)and enhanced CO_(2) absorption capacity(200 mg·g^(−)1),which synergistically activate C2H5OH and stabilize reaction intermediates.Structural characterization via FTIR and thermogravimetric analysis(TGA)confirmed the catalyst's thermal stability and recyclability,with no significant degradation observed over five reuse cycles(89%activity retention).In addition,the ionic liquid was also able to catalyze the synthesis of methyl propyl carbonate(PMC)and methyl butyl carbonate(BMC)at room temperature.展开更多
Modifying the electronic density of states and the synergistic effect of the active centers by introducing a second metal present an efficient strategy to tune physi/chemi-sorption,probably lead to improving catalytic...Modifying the electronic density of states and the synergistic effect of the active centers by introducing a second metal present an efficient strategy to tune physi/chemi-sorption,probably lead to improving catalytic performances.Herein,bimetallic Ni_(3)Mo/Al_(2)O_(3)catalyst was demonstrated and exhibited over 5 times more active than Pt/Al_(2)O_(3)toward the ethane dehydrogenation(EDH)as well as 2-10 times activity enhancement compared with their monometallic Ni and Mo counterparts and other Ni-based bimetallic nanoparticles.Kinetic studies revealed that the activation energy over Ni_(3)Mo/Al_(2)O_(3)(111 kJ mol^(-1))was much lower than that of Ni(157 kJ mol^(-1))and Mo(171 kJ·mol^(-1)).DFT calculations showed ethane was adsorbed on the Ni or Mo surface in a more parallel configuration,whereas over Ni_(3)Mo it adopted an inclined configuration.This change promoted ethane adsorption and pre-activation of the C-H bond,thereby benefiting the ethane dehydrogenation process on the Ni_(3)Mo surface.展开更多
Direct synthesis of high-value-added chemicals from low-carbon molecules is of great research importance.The C(sp^(3))–H bonds in alkanes exhibit a high bond dissociation energy and a very low polarity;consequently,a...Direct synthesis of high-value-added chemicals from low-carbon molecules is of great research importance.The C(sp^(3))–H bonds in alkanes exhibit a high bond dissociation energy and a very low polarity;consequently,achieving highly selective synthesis of esters through alkoxy carbonylation in heterogeneous catalysis is a particularly challenging process.Herein,we describe the immobilization of a single-atom palladium catalyst supported by porous organic polymers for highly selective ester formation in cycloalkane carbonylation,which achieves a selectivity as high as 82% and a benzyl alcohol conversion of up to 96%.Various catalytic characterization methods,including XRD,XPS,TEM,SEM,and FTIR,indicate that palladium species are uniformly distributed in the polymer.This work suggests a promising method for the design of hybrid catalytic systems and offers meaningful insights into the development of bifunctional catalysts for selective alkoxy carbonylation.展开更多
The development of heterogeneous catalysts with well-defined uniform isolated or multiple active sites is of great importance for understanding catalytic performances and studying reaction mechanisms.Herein,we present...The development of heterogeneous catalysts with well-defined uniform isolated or multiple active sites is of great importance for understanding catalytic performances and studying reaction mechanisms.Herein,we present a CoCu dual-atom catalyst(CoCu-DAC)where bonded Co-Cu dual-atom sites are embedded in N-doped carbon matrix with a well-defined Co(OH)CuN_(6)structure.The CoCu-DAC exhibits higher catalytic activity and selectivity than the Co single-atom catalyst(Co-SAC)and Cu single-atom catalyst(CuSAC)counterparts in the catalytic oxidative esterification of alcohols and a variety of methyl and alkyl esters have been successfully synthesized.Kinetic studies reveal that the activation energy(29.7 kJ mol^(-1))over CoCu-DAC is much lower than that over Co-SAC(38.4 kJ mol^(-1))and density functional theory(DFT)studies disclose that two different mechanisms are regulated over CoCu-DAC and Co-SAC/Cu-SAC in three-step esterification of alcohols.The bonded Co-Cu and adjacent N species efficiently catalyze the elementary reactions of alcohol dehydrogenation,O2activation and ester formation,respectively.The stepwise alkoxy pathway(O-H and C-H scissions)is preferred for both alcohol dehydrogenation and ester formation over CoCu-DAC,while the progressive hydroxylalkyl pathway(C-H and O-H scissions)for alcohol dehydrogenation and simultaneous hemiacetal dehydrogenation are favored over Co-SAC and Cu-SAC.Characteristic peaks in the Fourier transform infrared spectroscopy analysis may confirm the formation of the metal-C intermediate and the hydroxylalkyl pathway over Co-SAC.展开更多
The urgent need for sustainable chemical processes has driven the exploration of carbon dioxide(CO_(2))and dinitrogen(N_(2))as abundant,renewable feedstocks for producing value-added chemicals and fuels.This review fo...The urgent need for sustainable chemical processes has driven the exploration of carbon dioxide(CO_(2))and dinitrogen(N_(2))as abundant,renewable feedstocks for producing value-added chemicals and fuels.This review focuses on the transformation of CO_(2)and N_(2),highlighting their significance in green chemistry.We begin by discussing the fundamental principles of green chemistry and the advantages of utilizing CO_(2)and N_(2)to mitigate greenhouse gas emissions and reduce reliance on fossil resources.Subsequently,the review examines advanced transformation pathways for CO_(2)conversion,including electrocatalytic reduction,photocatalytic processes,and thermochemical transformations,evaluating their efficiency and scalability.The reduction of N_(2)and nitrogen oxides(NO_(x))to ammonia(NH_(3))is explored,presenting innovative alternatives to the traditional Haber-Bosch process that offer improved energy efficiency and lower environmental impact.Furthermore,the synthesis of nitrogenous compounds beyond NH_(3)is discussed,highlighting the versatility of green NH_(3)in the production of diverse chemicals.A key focus is placed on integrating CO_(2)and N_(2)transformations through C-N coupling reactions,enabling the direct formation of organic molecules with reduced environmental footprints.The review concludes by identifying current challenges and future directions,emphasizing the potential of catalytic technologies to foster a sustainable and resilient chemical industry.展开更多
基金supported by the National Key R&D Program of China(2017YFA0403103)the state of Mecklenburg-Vorpommern and the Bundesministerium für Bildung und Forschung~~
文摘The cycloaddition of epoxides and carbon dioxide represents a straightforward and atom-efficient method for synthesis of cyclic carbonates and utilization of CO2. So far, homogeneous metal complexes have been mainly applied for such transformations. Here, we describe the synthesis of novel heterogeneous Zn-based catalysts, which were conveniently prepared by pyrolysis of an active- carbon-supported phenanthroline-ligated Zn(OAc)2 complex. Detail structural characterizations proved the existence of single zinc sites in the active material. Compared to a Zn-based nanoparticle (Zn-NP) catalyst, the resulting single metal atom catalyst (SAC) displayed improved activity and stability for the cycloaddition of epoxides. By applying the optimal catalyst, a variety of carbonates were successfully obtained in high yields with good functional group tolerance.
基金supported by Shandong Energy Institute(SEI U202321)Gansu Province Young Talents(Team Project)(2025QNTD41)+2 种基金Natural Science Foundation of Shandong(ZR2024QB172)The Major Project of Gansu Province(21ZD4WA021,23JRRA603)Natural Science Foundation of Gansu(24JRRA060).
文摘This study reports the development of a novel amino‐functionalized ionic liquid catalyst,namely 1‐butyl‐3‐methylimidazolium amino triazole([EMIM]ATZ),for the efficient and sustainable synthesis of ethyl methyl carbonate(EMC)via transesterification of dimethyl carbonate(DMC)and ethanol(C_(2)H_(5)OH)at room temperature.Addressing the limitations of conventional catalytic systems that require elevated temperatures(>75℃),[EMIM]ATZ achieves 62%DMC conversion and 56%EMC yield within 8 h under room temperature(25℃),while conventional ionic liquids([EMIM]Cl,[EMIM]BF_(4),[EMIM]PF_(6) etc.)showed almost no activity at room temperature.The catalyst's superior activity stems from its strong basicity(pH≈9.2)and enhanced CO_(2) absorption capacity(200 mg·g^(−)1),which synergistically activate C2H5OH and stabilize reaction intermediates.Structural characterization via FTIR and thermogravimetric analysis(TGA)confirmed the catalyst's thermal stability and recyclability,with no significant degradation observed over five reuse cycles(89%activity retention).In addition,the ionic liquid was also able to catalyze the synthesis of methyl propyl carbonate(PMC)and methyl butyl carbonate(BMC)at room temperature.
文摘Modifying the electronic density of states and the synergistic effect of the active centers by introducing a second metal present an efficient strategy to tune physi/chemi-sorption,probably lead to improving catalytic performances.Herein,bimetallic Ni_(3)Mo/Al_(2)O_(3)catalyst was demonstrated and exhibited over 5 times more active than Pt/Al_(2)O_(3)toward the ethane dehydrogenation(EDH)as well as 2-10 times activity enhancement compared with their monometallic Ni and Mo counterparts and other Ni-based bimetallic nanoparticles.Kinetic studies revealed that the activation energy over Ni_(3)Mo/Al_(2)O_(3)(111 kJ mol^(-1))was much lower than that of Ni(157 kJ mol^(-1))and Mo(171 kJ·mol^(-1)).DFT calculations showed ethane was adsorbed on the Ni or Mo surface in a more parallel configuration,whereas over Ni_(3)Mo it adopted an inclined configuration.This change promoted ethane adsorption and pre-activation of the C-H bond,thereby benefiting the ethane dehydrogenation process on the Ni_(3)Mo surface.
基金supported by the National Natural Science Foundation of China (U22A20393,22202216)the Lanzhou Institute of Chemical Physics (E40199SR)。
文摘Direct synthesis of high-value-added chemicals from low-carbon molecules is of great research importance.The C(sp^(3))–H bonds in alkanes exhibit a high bond dissociation energy and a very low polarity;consequently,achieving highly selective synthesis of esters through alkoxy carbonylation in heterogeneous catalysis is a particularly challenging process.Herein,we describe the immobilization of a single-atom palladium catalyst supported by porous organic polymers for highly selective ester formation in cycloalkane carbonylation,which achieves a selectivity as high as 82% and a benzyl alcohol conversion of up to 96%.Various catalytic characterization methods,including XRD,XPS,TEM,SEM,and FTIR,indicate that palladium species are uniformly distributed in the polymer.This work suggests a promising method for the design of hybrid catalytic systems and offers meaningful insights into the development of bifunctional catalysts for selective alkoxy carbonylation.
基金supported by the National Natural Science Foundation of China(22372180 and 22202216)the Natural Science Foundation of Gansu Province and the Major Project of Gansu Province(21JR7RA096 and 21ZD4WA021)+2 种基金the Youth Innovation Promotion Association(2023441)Lanzhou Institute of Chemical Physics(LICP)Cooperation Foundation for Young Scholars(HZJJ21-06)Key Program of the Lanzhou Institute of Chemical Physics(KJZLZD-2)。
文摘The development of heterogeneous catalysts with well-defined uniform isolated or multiple active sites is of great importance for understanding catalytic performances and studying reaction mechanisms.Herein,we present a CoCu dual-atom catalyst(CoCu-DAC)where bonded Co-Cu dual-atom sites are embedded in N-doped carbon matrix with a well-defined Co(OH)CuN_(6)structure.The CoCu-DAC exhibits higher catalytic activity and selectivity than the Co single-atom catalyst(Co-SAC)and Cu single-atom catalyst(CuSAC)counterparts in the catalytic oxidative esterification of alcohols and a variety of methyl and alkyl esters have been successfully synthesized.Kinetic studies reveal that the activation energy(29.7 kJ mol^(-1))over CoCu-DAC is much lower than that over Co-SAC(38.4 kJ mol^(-1))and density functional theory(DFT)studies disclose that two different mechanisms are regulated over CoCu-DAC and Co-SAC/Cu-SAC in three-step esterification of alcohols.The bonded Co-Cu and adjacent N species efficiently catalyze the elementary reactions of alcohol dehydrogenation,O2activation and ester formation,respectively.The stepwise alkoxy pathway(O-H and C-H scissions)is preferred for both alcohol dehydrogenation and ester formation over CoCu-DAC,while the progressive hydroxylalkyl pathway(C-H and O-H scissions)for alcohol dehydrogenation and simultaneous hemiacetal dehydrogenation are favored over Co-SAC and Cu-SAC.Characteristic peaks in the Fourier transform infrared spectroscopy analysis may confirm the formation of the metal-C intermediate and the hydroxylalkyl pathway over Co-SAC.
基金supported by the National Key Research and Development Program of China(2024YFE0206400)the National Natural Science Foundation of China(22293015 and 22121002)+2 种基金the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA0390402)Chinese Academy Sciences Project for Young Scientists in Basic Research(YSBR-05O)Photon Science Center for Carbon Neutrality.
文摘The urgent need for sustainable chemical processes has driven the exploration of carbon dioxide(CO_(2))and dinitrogen(N_(2))as abundant,renewable feedstocks for producing value-added chemicals and fuels.This review focuses on the transformation of CO_(2)and N_(2),highlighting their significance in green chemistry.We begin by discussing the fundamental principles of green chemistry and the advantages of utilizing CO_(2)and N_(2)to mitigate greenhouse gas emissions and reduce reliance on fossil resources.Subsequently,the review examines advanced transformation pathways for CO_(2)conversion,including electrocatalytic reduction,photocatalytic processes,and thermochemical transformations,evaluating their efficiency and scalability.The reduction of N_(2)and nitrogen oxides(NO_(x))to ammonia(NH_(3))is explored,presenting innovative alternatives to the traditional Haber-Bosch process that offer improved energy efficiency and lower environmental impact.Furthermore,the synthesis of nitrogenous compounds beyond NH_(3)is discussed,highlighting the versatility of green NH_(3)in the production of diverse chemicals.A key focus is placed on integrating CO_(2)and N_(2)transformations through C-N coupling reactions,enabling the direct formation of organic molecules with reduced environmental footprints.The review concludes by identifying current challenges and future directions,emphasizing the potential of catalytic technologies to foster a sustainable and resilient chemical industry.
