Electrochemical reduction of CO_(2) to multi-carbon(C_(2))compounds presents an innovative strategy for the valorization of renewable energy into essential chemicals and fuels.However,the sluggish dynamics of carbon−c...Electrochemical reduction of CO_(2) to multi-carbon(C_(2))compounds presents an innovative strategy for the valorization of renewable energy into essential chemicals and fuels.However,the sluggish dynamics of carbon−carbon(C−C)coupling reaction directly impacts the efficiency and selectivity towards C_(2) products.Herein,we introduce a practical electrocatalytic design leveraging asymmetric*CO adsorption to facilitate C−C linkage.The synthesized a bimetallic catalyst,composed of single-atom zinc and copper clusters(Cu4),uniformly anchored on nitrogen-doped graphene(Zn_(1)Cu_(x)/NC).In-situ Raman spectroscopy and theoretical calculations revealed that the high*CO coverage promoted the C−C coupling reaction.Moreover,optimizing the anodic reaction environment further augments C_(2) product yields.Notably,this catalytic system achieves a high CO_(2)-to-C_(2) conversion yield of 84.9%at a commercially relevant current density of−100 mA/cm^(2),alongside urea oxidation reaction at the anode,making a significant progress in the electrochemical reduction of CO_(2) to valuable C_(2) products.展开更多
The reduction of N2 to NH_(3) is an important reaction for the industrial production of ammonia gas.Here,we theoretically study the thermal synthesis of ammonia catalyzed by Ru1@Mo_(2)CO_(x)single-atom catalyst(SAC),w...The reduction of N2 to NH_(3) is an important reaction for the industrial production of ammonia gas.Here,we theoretically study the thermal synthesis of ammonia catalyzed by Ru1@Mo_(2)CO_(x)single-atom catalyst(SAC),where Ru atoms are anchored on the oxygen vacancy of the defective Mo2COx.The results show that Ru1@Mo_(2)CO_(x)exhibits excellent stability,and can effectively adsorb and activate N2,owing to up to0.87|e|charge transfer from it to N2.The optimal pathway of N2-to-NH_(3) conversion is association pathway I,of which the rate-determining step is*NH_(2)→*NH_(3) with the barrier energy of 1.26 eV.Especially,the Mo_(2)CO_(x)center functions as an electron reservoir,donating electrons to the NxHy species,while the Ru single atom serves as a charge transfer pathway,thereby enhancing the reaction activity.This finding provides a theoretical foundation for the rational design of MXene-based SACs for thermal catalytic NH_(3) synthesis.展开更多
1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalizat...1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalization of unsymmetric 2-CF_(3)-1,3-enynes.The presence of trifluoromethyl group is determinable for the regioselectivity.When the CF_(3) group was replaced with the methyl or amide group,the regioselectivity decreased to a ratio of 1.3:1 or 1:1.7,respectively.For alkyl substitutedβ-CF_(3)-1,3-enynes,a regiospecificity was obtained.This strategy features excellent regioselectivity,broad substrate scope and high functional group tolerance.Mechanistic studies showed that C–H bond activation is the rate-limiting step.展开更多
环己酮肟气相Beckmann重排反应RBS-1催化剂在高温反应时易失活,导致催化剂费用居高不下。为提高技术经济性,实现失活催化剂性能的高效恢复,系统研究RBS-1催化剂失活机理、再生手段及催化性能。采用N_(2)物理吸附-脱附技术考察催化剂失...环己酮肟气相Beckmann重排反应RBS-1催化剂在高温反应时易失活,导致催化剂费用居高不下。为提高技术经济性,实现失活催化剂性能的高效恢复,系统研究RBS-1催化剂失活机理、再生手段及催化性能。采用N_(2)物理吸附-脱附技术考察催化剂失活前后与再生前后的比表面积及孔结构变化,并结合XRD、FT-IR和^(29)Si MAS NMR表征技术探讨了RBS-1催化剂在失活与再生过程中活性中心的演变规律。研究发现,失活RBS-1催化剂物相结构保持完好,但BET比表面积和孔体积均有明显降低,说明催化剂失活主要为积炭覆盖催化剂活性位点并堵塞孔道所致。针对积炭堵孔导致的催化剂失活问题,采用烧炭、含氮化合物改性处理构建巢式硅羟基活性位点等手段对失活催化剂进行再生研究。结果表明,在530℃下烧炭能将催化剂表面及孔道内的大部分积炭烧除,催化剂性能可恢复90%以上;对脱炭后的催化剂进一步改性处理,最优催化剂性能可恢复98%以上。展开更多
Methane’s complete catalytic oxidation process has been widely studied,but efficient catalytic oxidation of low-concentration methane(≤0.75%)remains a crucial problem in the coal chemical industry.How to prevent the...Methane’s complete catalytic oxidation process has been widely studied,but efficient catalytic oxidation of low-concentration methane(≤0.75%)remains a crucial problem in the coal chemical industry.How to prevent the sintering deactivation of the active component in Pd-based catalysts and achieve efficient and stable operation of sub-nanometer catalysts remains challenging.Here,we utilize the interaction between amine ligands and Pd nanoparticles to stabilize and encapsulate the Pd particles within the pores of a molecular sieve carrier,effectively promoting the high dispersion of Pd particles.By leveraging the low acidity,high hydrophobicity,and high hydrothermal stability of the zeolite carrier,the Pd@S-1 catalyst exhibits excellent activity and stability in the catalytic oxidation of methane at lowconcentrations.Finally,density functional theory is employed to investigate the reaction mechanism of low-concentration methane during the catalytic process.Encapsulating the active metal component in zeolite to improve catalytic activity and stability provides a theoretical basis and direction for preparing complete oxidation catalysts for low-concentration methane.展开更多
Electrocatalytic conversion of carbon dioxide(CO_(2))offers an effective method of CO_(2)fixation to mitigate global warming and the energy crisis.However,for supported Ni single-atom catalysts(SACs),which are among t...Electrocatalytic conversion of carbon dioxide(CO_(2))offers an effective method of CO_(2)fixation to mitigate global warming and the energy crisis.However,for supported Ni single-atom catalysts(SACs),which are among the most promising candidates for this application,the relationship between Ni coordination structure and catalytic properties is still under strong debate.Here,we fabricated a series of Ni SACs through precise-engineering of anchor sites on nitrogen-doped carbon(NC)followed by Ni atom anchoring using atomic layer deposition.Among them,a Ni_(1)/NC SAC,with a coordination number(CN)of four but less pyridinic nitrogen(N_(pyri)),achieved over 90%faradaic efϐiciency for CO at potentials from-0.7 to-1.0 V and a mass activity of 6.5 A/mgNi at-0.78 V along with high stability,outperforming other Ni SACs with lower CN and more N_(pyri).Theoretical calculations of various three and four-coordinated Ni_(1)-NxCy structures revealed a linear correlation between the reaction Gibbs free energy for the potential-limiting step and the highest occupied molecular orbital(HOMO)position of Ni-3d orbitals,therein the four-coordinated Ni_(1)-N_(1)C_(3)with the highest HOMO position is identified as the active site for the electrocatalytic CO_(2)-to-CO process,in line with the experimental results.展开更多
The electrochemical CO_(2)reduction reaction(CO_(2)RR)is considered a promising technology for converting atmospheric CO_(2)into valuable chemicals.It is a significant way to mitigate the shortage of fossil energy and...The electrochemical CO_(2)reduction reaction(CO_(2)RR)is considered a promising technology for converting atmospheric CO_(2)into valuable chemicals.It is a significant way to mitigate the shortage of fossil energy and store excessive renewable electricity in fuels to maintain carbon neutrality.Considering the substantially reduced cost of clean electricity,C1 molecule unitization has emerged as a competitive strategy for room-temperature electrolysis.However,the practical implementation of CO_(2)RR has been hindered by low desired product selectivity,high overpotential,and undesirable hydrogen evolution reactions(HER).Consequently,it is imperative to execute a timely assessment of advanced strategies in CO_(2)RR,with emphasis on catalytic design strategies,understanding of structure–activity relationships,and deactivation of catalysts.In this context,it is imperative to investigate the intrinsic active sites and reaction mechanisms.This review focuses on the design of novel catalysts and their active sites via operando techniques.The combination of advanced characterization techniques and theoretical calculations provides a high-throughput way to obtain a deeper understanding of the reaction mechanism.Furthermore,optimization of the interplay between the catalyst surface and reaction intermediate disturbs the linear correlation between the adsorption energies of the intermediates,resulting in a convoluted cascade system.The appropriate strategies for CO_(2)RR,challenges,and future approaches are projected in this review to stimulate major innovations.Moreover,the plausible research directions are discussed for producing C_(1)chemicals via electrochemical CO_(2)RR at room temperature.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22276104 and T2341002)。
文摘Electrochemical reduction of CO_(2) to multi-carbon(C_(2))compounds presents an innovative strategy for the valorization of renewable energy into essential chemicals and fuels.However,the sluggish dynamics of carbon−carbon(C−C)coupling reaction directly impacts the efficiency and selectivity towards C_(2) products.Herein,we introduce a practical electrocatalytic design leveraging asymmetric*CO adsorption to facilitate C−C linkage.The synthesized a bimetallic catalyst,composed of single-atom zinc and copper clusters(Cu4),uniformly anchored on nitrogen-doped graphene(Zn_(1)Cu_(x)/NC).In-situ Raman spectroscopy and theoretical calculations revealed that the high*CO coverage promoted the C−C coupling reaction.Moreover,optimizing the anodic reaction environment further augments C_(2) product yields.Notably,this catalytic system achieves a high CO_(2)-to-C_(2) conversion yield of 84.9%at a commercially relevant current density of−100 mA/cm^(2),alongside urea oxidation reaction at the anode,making a significant progress in the electrochemical reduction of CO_(2) to valuable C_(2) products.
基金the financial support from National Natural Science Foundation of China(22479032,22363001 and 22250710677)the NSFC Center for Single-Atom Catalysis(22388102)+2 种基金the National Key R&D Project(2022YFA1503900)the Natural Science Special Foundation of Guizhou University(No.202140)Guizhou Provincial Key Laboratory Platform Project(ZSYS[2025]008).
文摘The reduction of N2 to NH_(3) is an important reaction for the industrial production of ammonia gas.Here,we theoretically study the thermal synthesis of ammonia catalyzed by Ru1@Mo_(2)CO_(x)single-atom catalyst(SAC),where Ru atoms are anchored on the oxygen vacancy of the defective Mo2COx.The results show that Ru1@Mo_(2)CO_(x)exhibits excellent stability,and can effectively adsorb and activate N2,owing to up to0.87|e|charge transfer from it to N2.The optimal pathway of N2-to-NH_(3) conversion is association pathway I,of which the rate-determining step is*NH_(2)→*NH_(3) with the barrier energy of 1.26 eV.Especially,the Mo_(2)CO_(x)center functions as an electron reservoir,donating electrons to the NxHy species,while the Ru single atom serves as a charge transfer pathway,thereby enhancing the reaction activity.This finding provides a theoretical foundation for the rational design of MXene-based SACs for thermal catalytic NH_(3) synthesis.
基金supported by National Natural Science Founda:tion of China(22461002,22308061,22305046)Natural Science Foundation(NSF)of Jiangxi Province(20224BAB213011,20242BAB20110,20224BAB213012)+1 种基金High-Level and Highly Demanded Overseas Talent Programs of Jiangxi Province(20232BCJ25050)Gannan Normal University Start-up Fund(BSJJ202109).
文摘1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalization of unsymmetric 2-CF_(3)-1,3-enynes.The presence of trifluoromethyl group is determinable for the regioselectivity.When the CF_(3) group was replaced with the methyl or amide group,the regioselectivity decreased to a ratio of 1.3:1 or 1:1.7,respectively.For alkyl substitutedβ-CF_(3)-1,3-enynes,a regiospecificity was obtained.This strategy features excellent regioselectivity,broad substrate scope and high functional group tolerance.Mechanistic studies showed that C–H bond activation is the rate-limiting step.
文摘环己酮肟气相Beckmann重排反应RBS-1催化剂在高温反应时易失活,导致催化剂费用居高不下。为提高技术经济性,实现失活催化剂性能的高效恢复,系统研究RBS-1催化剂失活机理、再生手段及催化性能。采用N_(2)物理吸附-脱附技术考察催化剂失活前后与再生前后的比表面积及孔结构变化,并结合XRD、FT-IR和^(29)Si MAS NMR表征技术探讨了RBS-1催化剂在失活与再生过程中活性中心的演变规律。研究发现,失活RBS-1催化剂物相结构保持完好,但BET比表面积和孔体积均有明显降低,说明催化剂失活主要为积炭覆盖催化剂活性位点并堵塞孔道所致。针对积炭堵孔导致的催化剂失活问题,采用烧炭、含氮化合物改性处理构建巢式硅羟基活性位点等手段对失活催化剂进行再生研究。结果表明,在530℃下烧炭能将催化剂表面及孔道内的大部分积炭烧除,催化剂性能可恢复90%以上;对脱炭后的催化剂进一步改性处理,最优催化剂性能可恢复98%以上。
基金supported by the National Natural Science Foundation of China(No.52270114)the State key laboratory of coal mine disaster dynamics and control(No.2011DA105827-FW202210).
文摘Methane’s complete catalytic oxidation process has been widely studied,but efficient catalytic oxidation of low-concentration methane(≤0.75%)remains a crucial problem in the coal chemical industry.How to prevent the sintering deactivation of the active component in Pd-based catalysts and achieve efficient and stable operation of sub-nanometer catalysts remains challenging.Here,we utilize the interaction between amine ligands and Pd nanoparticles to stabilize and encapsulate the Pd particles within the pores of a molecular sieve carrier,effectively promoting the high dispersion of Pd particles.By leveraging the low acidity,high hydrophobicity,and high hydrothermal stability of the zeolite carrier,the Pd@S-1 catalyst exhibits excellent activity and stability in the catalytic oxidation of methane at lowconcentrations.Finally,density functional theory is employed to investigate the reaction mechanism of low-concentration methane during the catalytic process.Encapsulating the active metal component in zeolite to improve catalytic activity and stability provides a theoretical basis and direction for preparing complete oxidation catalysts for low-concentration methane.
文摘Electrocatalytic conversion of carbon dioxide(CO_(2))offers an effective method of CO_(2)fixation to mitigate global warming and the energy crisis.However,for supported Ni single-atom catalysts(SACs),which are among the most promising candidates for this application,the relationship between Ni coordination structure and catalytic properties is still under strong debate.Here,we fabricated a series of Ni SACs through precise-engineering of anchor sites on nitrogen-doped carbon(NC)followed by Ni atom anchoring using atomic layer deposition.Among them,a Ni_(1)/NC SAC,with a coordination number(CN)of four but less pyridinic nitrogen(N_(pyri)),achieved over 90%faradaic efϐiciency for CO at potentials from-0.7 to-1.0 V and a mass activity of 6.5 A/mgNi at-0.78 V along with high stability,outperforming other Ni SACs with lower CN and more N_(pyri).Theoretical calculations of various three and four-coordinated Ni_(1)-NxCy structures revealed a linear correlation between the reaction Gibbs free energy for the potential-limiting step and the highest occupied molecular orbital(HOMO)position of Ni-3d orbitals,therein the four-coordinated Ni_(1)-N_(1)C_(3)with the highest HOMO position is identified as the active site for the electrocatalytic CO_(2)-to-CO process,in line with the experimental results.
基金funded by a National Research Council of Science&Technology grant from the Ministry of Science and ICT(MSIT),Republic of Korea(No.CAP21012-100)the Korea Institute of Energy Technology Evaluation and Planning(KETEP)under the Ministry of Trade,Industry&Energy(MOTIE),Republic of Korea(No.20224C10300010)。
文摘The electrochemical CO_(2)reduction reaction(CO_(2)RR)is considered a promising technology for converting atmospheric CO_(2)into valuable chemicals.It is a significant way to mitigate the shortage of fossil energy and store excessive renewable electricity in fuels to maintain carbon neutrality.Considering the substantially reduced cost of clean electricity,C1 molecule unitization has emerged as a competitive strategy for room-temperature electrolysis.However,the practical implementation of CO_(2)RR has been hindered by low desired product selectivity,high overpotential,and undesirable hydrogen evolution reactions(HER).Consequently,it is imperative to execute a timely assessment of advanced strategies in CO_(2)RR,with emphasis on catalytic design strategies,understanding of structure–activity relationships,and deactivation of catalysts.In this context,it is imperative to investigate the intrinsic active sites and reaction mechanisms.This review focuses on the design of novel catalysts and their active sites via operando techniques.The combination of advanced characterization techniques and theoretical calculations provides a high-throughput way to obtain a deeper understanding of the reaction mechanism.Furthermore,optimization of the interplay between the catalyst surface and reaction intermediate disturbs the linear correlation between the adsorption energies of the intermediates,resulting in a convoluted cascade system.The appropriate strategies for CO_(2)RR,challenges,and future approaches are projected in this review to stimulate major innovations.Moreover,the plausible research directions are discussed for producing C_(1)chemicals via electrochemical CO_(2)RR at room temperature.
