The efficiency of organic semiconductor photocatalysts is typically limited by their capability of photogenerated electron transport.Herein,a photocatalyst is proposed initially through the specific axial coordination...The efficiency of organic semiconductor photocatalysts is typically limited by their capability of photogenerated electron transport.Herein,a photocatalyst is proposed initially through the specific axial coordination interaction between imidazole-C_(60)(ImC_(60))and zinc tetraphenyl porphyrin(ZnTPP)named ImC_(60)-ZnTPP.Subsequently,detailed structural characterizations along with theoretical calculation reveal that the unique ImC_(60)-ZnTPP possesses head-to-tail stacking supra-structures,leading to the formation of a continuous array of C_(60)–C_(60) with ultrashort spacing and ensuring strongπ–πinteractions and homogeneous electronic coupling,which could tremendously promote electron transport along the(−111)crystal facet of ImC_(60)-ZnTPP.Consequently,compared to other fullerene-based photocatalysts,ImC_(60)-ZnTPP shows exceptional photocatalytic hydrogen production activity,with an efficiency of up to 80.95 mmol g^(-1) h^(-1).This study provides a novel strategy to design highly efficient fullerene-based photocatalytic systems for solar-driven energy conversion and extend their artificial photosynthetic use.展开更多
Atomically ordered precious intermetallic nanoparticles have garnered significant attention for diverse applications due to their well-defined surface atomic arrangements and exceptional electronic and geometric prope...Atomically ordered precious intermetallic nanoparticles have garnered significant attention for diverse applications due to their well-defined surface atomic arrangements and exceptional electronic and geometric properties.However,synthesizing non-precious ordered intermetallics that exhibit high stability under operating conditions remains a formidable challenge,primarily owing to their strong oxyphilicity,highly negative reduction potentials,and low corrosion resistance.In this work,we report a facile yet versatile seed-mediated solid-phase approach for fabricating uniform Ni_(3)Ga_(1) intermetallic nanocubes(NCs)fully encapsulated within N-doped carbon layers(denoted as Ni_(3)Ga_(1)@NC-800).Extensive characterization confirms the formation of a unique core-shell architecture,with atomic-resolution structural analysis and X-ray absorption fine structure measurements unequivocally verifying the atomically ordered Ni_(3)Ga_(1) intermetallic phase.The Ni_(3)Ga_(1)@NC-800 catalyst demonstrates exceptional performance in the 1,4-hydrogenation of α,β-unsaturated carbonyl compounds,exhibiting both remarkable activity and exclusive selectivity while maintaining high stability over multiple reaction cycles without observable performance decay.Combined experimental and theoretical calculations reveal that the strong interatomic p-d orbital hybridization facilitates electron transfer from Ga to Ni atoms,resulting in electron localization on ordered Ni atoms.This electronic configuration positively influences H_(2)activation and optimizes substrate adsorption strength,thereby substantially improving catalytic efficiency.Furthermore,this synthetic strategy proves generalizable,successfully extending to the synthesis of other non-precious ordered Ni_(1)Sn_(1) and Ni_(2)In_(3) intermetallics confined within N-doped carbon matrices.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
To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic ef...To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.展开更多
Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hyd...Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hydrogen evolution reaction is enhanced under acidic conditions.Here,we report that the CO_(2) can be efficiently reduced into CH_(4) over a Cu catalyst by modifying with a glutamic acid molecule under acidic conditions.The CH_(4) Faradaic efficiency can reach 62.9% with a current density of 450 mA cm^(-2).Meanwhile,a single-pass carbon efficiency of 48.1% toward CH_(4) is achieved.Experiments revealed that the glutamic acid molecule can enhance the concentration of Kt on the surface of Cu,which can suppress the HER and promote CO_(2) reduction,resulting in high selectivity of CH_(4) under acidic conditions.展开更多
Cu-based electrocatalysts can have excellent activity for the generation of C_(2+)products from a CO_(2)reduction reaction(CO_(2)RR).Cuδ+species is crucial in tuning the performance of the catalysts.Herein,we discove...Cu-based electrocatalysts can have excellent activity for the generation of C_(2+)products from a CO_(2)reduction reaction(CO_(2)RR).Cuδ+species is crucial in tuning the performance of the catalysts.Herein,we discovered that Si-doped Cu catalysts had excellent performance for electrochemical CO_(2)to C_(2+)products.A high Faradaic efficiency(FE)of 84.7%was achieved with a current density of 289mA cm^(−2)in the flow-cell system.In situ experimental results showed that the significant reconstruction occurred during the electrolysis,resulting in the formation of the asymmetric Cu sites(Cu^(0)-Cu^(+)).The ratio of Cu^(0)and Cu^(+)could be tuned by changing Si content.Controlled experiments and theoretical calculations demonstrated that the asymmetric Cu sites caused by the appropriate Si doping promoted CO_(2)activation and strengthened the adsorption of^(*)CO intermediate.This was beneficial to the subsequent^(*)CO–^(*)CO dimerization step,and thus,accounted for the enhancement of C_(2+)selectivity.展开更多
The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.In...The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.Initially,the N_(2)-bridging end-on dititanium side-on dipotassium complex[{(Tren^(TMS))Ti}_(2)(μ-η^(1):η^(1):η^(2):η^(2)-N_(2)K_(2))] underwent simultaneous disproportionation and N-methylation reactions in the presence of methyl trifluoromethanesulfonate(Me OTf),yielding [{(N^(Me,TMS)NN^(TMS)_(2))Ti}(μ-NMe)]_(2) with complete cleavage of the N≡N bond.The nucleophilicity of the N-methylated intermediate allowed it to react with electrophilic reagents such as trimethylchlorosilane(TMSCl) to form heptamethyldisilazane,or with acyl chlorides to generate N-methylimides.Moreover,nitrogen-15(^(15)N) labeled experiments provided a novel approach to synthesizing ^(15)N-labeled methylimides.展开更多
Biomass represents an abundant and sustainable carbon resource to partially replace fossil resources for producing essential chemicals,alleviating energy and carbon emission issues associated with the traditional chem...Biomass represents an abundant and sustainable carbon resource to partially replace fossil resources for producing essential chemicals,alleviating energy and carbon emission issues associated with the traditional chemical industry.For instance,2,5-furandicarboxylic acid(FDCA)is one of the valuable biomass-derived chemicals,and is an excellent alternative to petroleum-based terephthalic acid for plastics.展开更多
Two-dimensional(2D)oxide nanomaterials have great potential for various applications but face challenges due to strong interlayer interactions.In this work,we propose a novel and facile method to exfoliate layered tra...Two-dimensional(2D)oxide nanomaterials have great potential for various applications but face challenges due to strong interlayer interactions.In this work,we propose a novel and facile method to exfoliate layered transition metal oxides into ultrathin nanosheets functionalized with phosphate species by the combination of ball-milling and liquid-exfoliation with phosphoric acid.The resulting HNb Mo O6nanosheets with supported Pd nanoparticles displayed excellent catalytic performance in the one-pot conversion of phenol into caprolactam(CPL),achieving a yield of up to 71.9%.This one-pot route avoids the energy-intensive intermediate separation process in conventional multi-step approaches to CPL.The superior catalytic performance of the catalysts is attributed to the tunable Bronsted acid/Lewis acid ratio and readily accessible active sites on the ultrathin nanosheets.This research demonstrates a new methodology for constructing ultrathin nanosheets and preparing bifunctional catalysts for tandem reactions,which opens the way for one-pot production of CPL.展开更多
The development of efficient Cu-based heterogeneous catalysts for CO_(2) hydrogenation to methanol has been an appealing subject.Inspired by the concept of inverse catalysts,a series of La_(2)O_(2)CO_(3)/Cu nanorod co...The development of efficient Cu-based heterogeneous catalysts for CO_(2) hydrogenation to methanol has been an appealing subject.Inspired by the concept of inverse catalysts,a series of La_(2)O_(2)CO_(3)/Cu nanorod composites with varying Cu contents(denoted as LOC/Cu-x,where x stands for the mass ratio of La and Cu in the catalysts)were prepared by combining coprecipitation and calcination processes.Remarkable composition-dependence of catalytic activity and selectivity were observed when different LOC/Cu-x(x=0.1,0.2,0.5,1,3 and 5)were used to catalyze the CO_(2) hydrogenation.The predominant product shifted from methane to methanol with the increasing Cu content.The highest reaction rate(13.3 mmol·gCu^(-1)·h^(-1))and methanol selectivity(85.5%)were achieved when LOC/Cu-1 was tested at 200℃.The LOC was not active for the reaction,while the Cu itself displayed poor catalytic performance.The Cu–LOC interactions significantly affected the nature of the catalysts,including mutual electron transfer,crystal structure,morphology,porosity,surface Cu valence and capability of adsorbing the reactant gases,etc.,which account for the outstanding behavior of the LOC/Cu-1 catalyst.This work provides a new strategy for the design and optimization of Cu-based catalysts.展开更多
Plastic waste is causing serious environmental problems. Developing efficient, cheap and stable catalytic routes to convert plastic waste into valuable products is of great importance for sustainable development, but ...Plastic waste is causing serious environmental problems. Developing efficient, cheap and stable catalytic routes to convert plastic waste into valuable products is of great importance for sustainable development, but remains to be a challenging task. Zeolites are cheap and stable, but they are usually not efficient for plastic conversion at a low temperature. Herein a series of microporous and mesoporous zeolites were used to study the influence of porosity and acidity of zeolite on catalytic activity for plastics conversion. It was observed that H-Beta zeolite was an efficient catalyst for cracking high-density polyethylene to gasoline at 240℃, and the products were almost C_(4)–C_(12) alkanes. The effect of porosity and acidity on catalytic performance of zeolites was evaluated, which clearly visualized the good performance of H-Beta due to high surface area, large channel system, large amount accessible acidic sites. This study provides very useful information for designing zeolites for efficient conversion of plastics.展开更多
The greenhouse gas CO_(2)emitted in the process of fossil fuels utilization can be decontaminated through carbon capture,utilization and storage technology(CCUS),which is an important pathway to close the carbon cycle...The greenhouse gas CO_(2)emitted in the process of fossil fuels utilization can be decontaminated through carbon capture,utilization and storage technology(CCUS),which is an important pathway to close the carbon cycle and achieve carbon neutrality[1,2].In recent years,catalyzing CO_(2)reduction into high value-added C_(2+) products with high selectivity by electrochemical method has become a promising research area.Compared to C1products(such as CO,methane,formic acid and methanol),C_(2+)products(such as ethylene,ethanol,acetic acid and n-propanol)have higher energy density and economic value.At present,the main C1products of CO_(2)reduction reaction(CO_(2)RR),such as CO and formic acid,can achieve more than 90%selectivity and meet the industrial current density requirements of 300 mA cm^(-2)[3].However,the single selectivity and current density of C_(2+)products are still facing great challenges,mainly due to the complex reaction route,slow kinetic process,low catalyst activity and lack of exploration of mechanism,which make it difficult to meet the needs of large-scale production.展开更多
The creation of universal strategies to affect the reaction route of the electroreduction of CO_(2) is critical.Here,we report the first work to introduce cations into diverse metals such as Cu,Bi,In,and Sn via the el...The creation of universal strategies to affect the reaction route of the electroreduction of CO_(2) is critical.Here,we report the first work to introduce cations into diverse metals such as Cu,Bi,In,and Sn via the electroreduction of related metallic oxides in quaternary ammonium surfactant solutions.Compared to their physical adsorption,cations embedded into the electrodes have a more pronounced impact on the electrical field,which effectively influences the adsorption state of intermediates.With the increase of surface field,the hydrogen evolution reaction and*COOH route are significantly reduced,favouring the*OCHO pathway instead.As a result,hydrogen,CO,and C_(2+)products almost completely vanish at−0.5 V versus RHE in 0.1 M Na_(2)SO_(4)in an H-type cell after enough cations are embedded into the Cu electrode,and the faradaic efficiency of formate rises from 18.0%to 99.5%simultaneously.展开更多
Electroreduction of carbon dioxide(CO_(2))into valuable chemicals and fuels is a promising strategy to mitigate energy and environmental problems.However,the poor selectivity and inadequate electrochemical stability p...Electroreduction of carbon dioxide(CO_(2))into valuable chemicals and fuels is a promising strategy to mitigate energy and environmental problems.However,the poor selectivity and inadequate electrochemical stability prevent practical applications.In this work,we prepared ultrasmall copper(Cu)nanoparticles by using tannic acid as a complexing agent and stablizer.The ultrasmall Cu nanoparticles(3.4 nm)exhibited outstanding performance for CO_(2)electroreduction to CH_(4).The Faradaic efficiency of CH_(4)could reach up to 68%at-1.2 V versus reversible hydrogen electrode(RHE),with high current density of 475 mA·cm^(-2).The ultrasmall Cu nanoparticles could enhance the CO adsorption and H2O activation,resulting in the high selectivity of CH_(4).展开更多
The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to...The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction pathways.In this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)conversion.The doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)concentration.Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of*NO.This alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).展开更多
基金supported by the National Natural Science Foundation of China(52322204,52072374,52272052)the National Key R&D Program of China(Grant No.2022YFA1205900)the Youth Innovation Promotion Association of CAS(Y2022015).
文摘The efficiency of organic semiconductor photocatalysts is typically limited by their capability of photogenerated electron transport.Herein,a photocatalyst is proposed initially through the specific axial coordination interaction between imidazole-C_(60)(ImC_(60))and zinc tetraphenyl porphyrin(ZnTPP)named ImC_(60)-ZnTPP.Subsequently,detailed structural characterizations along with theoretical calculation reveal that the unique ImC_(60)-ZnTPP possesses head-to-tail stacking supra-structures,leading to the formation of a continuous array of C_(60)–C_(60) with ultrashort spacing and ensuring strongπ–πinteractions and homogeneous electronic coupling,which could tremendously promote electron transport along the(−111)crystal facet of ImC_(60)-ZnTPP.Consequently,compared to other fullerene-based photocatalysts,ImC_(60)-ZnTPP shows exceptional photocatalytic hydrogen production activity,with an efficiency of up to 80.95 mmol g^(-1) h^(-1).This study provides a novel strategy to design highly efficient fullerene-based photocatalytic systems for solar-driven energy conversion and extend their artificial photosynthetic use.
基金financially supported by the program of the National Natural Science Foundation of Shandong Province(No.ZR2023ZD23)the Shandong Province Key Research and Development Plan(No.2023CXGC010607).
文摘Atomically ordered precious intermetallic nanoparticles have garnered significant attention for diverse applications due to their well-defined surface atomic arrangements and exceptional electronic and geometric properties.However,synthesizing non-precious ordered intermetallics that exhibit high stability under operating conditions remains a formidable challenge,primarily owing to their strong oxyphilicity,highly negative reduction potentials,and low corrosion resistance.In this work,we report a facile yet versatile seed-mediated solid-phase approach for fabricating uniform Ni_(3)Ga_(1) intermetallic nanocubes(NCs)fully encapsulated within N-doped carbon layers(denoted as Ni_(3)Ga_(1)@NC-800).Extensive characterization confirms the formation of a unique core-shell architecture,with atomic-resolution structural analysis and X-ray absorption fine structure measurements unequivocally verifying the atomically ordered Ni_(3)Ga_(1) intermetallic phase.The Ni_(3)Ga_(1)@NC-800 catalyst demonstrates exceptional performance in the 1,4-hydrogenation of α,β-unsaturated carbonyl compounds,exhibiting both remarkable activity and exclusive selectivity while maintaining high stability over multiple reaction cycles without observable performance decay.Combined experimental and theoretical calculations reveal that the strong interatomic p-d orbital hybridization facilitates electron transfer from Ga to Ni atoms,resulting in electron localization on ordered Ni atoms.This electronic configuration positively influences H_(2)activation and optimizes substrate adsorption strength,thereby substantially improving catalytic efficiency.Furthermore,this synthetic strategy proves generalizable,successfully extending to the synthesis of other non-precious ordered Ni_(1)Sn_(1) and Ni_(2)In_(3) intermetallics confined within N-doped carbon matrices.
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.
基金supported by National Natural Science Foundation of China (22033009, 22121002, 22238011)。
文摘To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.
基金supported by the National Key Research and Development Program of China(2020YFA0710201)the China Postdoctoral Science Foundation Funded Project(2021M701211)+1 种基金Fundamental Research Funds for the Central Universities,“Island Atmosphere and Ecology”Category Ⅳ Peak Discipline(No.QN202505)the National Natural Science Foundation of China(22293015,22121002).
文摘Electroreduction of CO_(2) into CH_(4) under acidic conditions is a promising strategy for CO_(2) utilization,which allows for high CO_(2) conversion efficiency.However,the selectivity of CH_(4) is low because the hydrogen evolution reaction is enhanced under acidic conditions.Here,we report that the CO_(2) can be efficiently reduced into CH_(4) over a Cu catalyst by modifying with a glutamic acid molecule under acidic conditions.The CH_(4) Faradaic efficiency can reach 62.9% with a current density of 450 mA cm^(-2).Meanwhile,a single-pass carbon efficiency of 48.1% toward CH_(4) is achieved.Experiments revealed that the glutamic acid molecule can enhance the concentration of Kt on the surface of Cu,which can suppress the HER and promote CO_(2) reduction,resulting in high selectivity of CH_(4) under acidic conditions.
基金the National Natural Science Foundation of China(grant nos.22203050,22002172,22293015,22033009,and 22121002)Natural Scientific Foundation of Shandong(grant no.ZR2022QB002)+1 种基金Beijing Natural Science Foundation(grant no.J210020)Photon Science Center for Carbon Neutrality,and CAS Project for Young Scientists in Basic Research(YSBR-050).
文摘Cu-based electrocatalysts can have excellent activity for the generation of C_(2+)products from a CO_(2)reduction reaction(CO_(2)RR).Cuδ+species is crucial in tuning the performance of the catalysts.Herein,we discovered that Si-doped Cu catalysts had excellent performance for electrochemical CO_(2)to C_(2+)products.A high Faradaic efficiency(FE)of 84.7%was achieved with a current density of 289mA cm^(−2)in the flow-cell system.In situ experimental results showed that the significant reconstruction occurred during the electrolysis,resulting in the formation of the asymmetric Cu sites(Cu^(0)-Cu^(+)).The ratio of Cu^(0)and Cu^(+)could be tuned by changing Si content.Controlled experiments and theoretical calculations demonstrated that the asymmetric Cu sites caused by the appropriate Si doping promoted CO_(2)activation and strengthened the adsorption of^(*)CO intermediate.This was beneficial to the subsequent^(*)CO–^(*)CO dimerization step,and thus,accounted for the enhancement of C_(2+)selectivity.
基金Financial supports from the National Natural Science Foundation of China (Nos.22025109,22371283)the National Key R&D Program of China (No.2023YFA1507902)+1 种基金CAS Project for Young Scientists in Basic Research (No.YSBR-050)the State Key Laboratory of Fine Chemicals,Dalian University of Technology (No.KF2102) are gratefully acknowledged。
文摘The direct transformation of dinitrogen(N_(2)) into nitrogen-containing organic compounds holds substantial importance.In this work,we report a titanium-promoted method for the conversion of N_(2) to N-methylimides.Initially,the N_(2)-bridging end-on dititanium side-on dipotassium complex[{(Tren^(TMS))Ti}_(2)(μ-η^(1):η^(1):η^(2):η^(2)-N_(2)K_(2))] underwent simultaneous disproportionation and N-methylation reactions in the presence of methyl trifluoromethanesulfonate(Me OTf),yielding [{(N^(Me,TMS)NN^(TMS)_(2))Ti}(μ-NMe)]_(2) with complete cleavage of the N≡N bond.The nucleophilicity of the N-methylated intermediate allowed it to react with electrophilic reagents such as trimethylchlorosilane(TMSCl) to form heptamethyldisilazane,or with acyl chlorides to generate N-methylimides.Moreover,nitrogen-15(^(15)N) labeled experiments provided a novel approach to synthesizing ^(15)N-labeled methylimides.
文摘Biomass represents an abundant and sustainable carbon resource to partially replace fossil resources for producing essential chemicals,alleviating energy and carbon emission issues associated with the traditional chemical industry.For instance,2,5-furandicarboxylic acid(FDCA)is one of the valuable biomass-derived chemicals,and is an excellent alternative to petroleum-based terephthalic acid for plastics.
基金supported by the National Key Research and Development Program of China(2022YFA1504901,2023YFA1508103)the National Natural Science Foundation of China(22293012,22179132,22293015,22121002)。
文摘Two-dimensional(2D)oxide nanomaterials have great potential for various applications but face challenges due to strong interlayer interactions.In this work,we propose a novel and facile method to exfoliate layered transition metal oxides into ultrathin nanosheets functionalized with phosphate species by the combination of ball-milling and liquid-exfoliation with phosphoric acid.The resulting HNb Mo O6nanosheets with supported Pd nanoparticles displayed excellent catalytic performance in the one-pot conversion of phenol into caprolactam(CPL),achieving a yield of up to 71.9%.This one-pot route avoids the energy-intensive intermediate separation process in conventional multi-step approaches to CPL.The superior catalytic performance of the catalysts is attributed to the tunable Bronsted acid/Lewis acid ratio and readily accessible active sites on the ultrathin nanosheets.This research demonstrates a new methodology for constructing ultrathin nanosheets and preparing bifunctional catalysts for tandem reactions,which opens the way for one-pot production of CPL.
基金The work was financially supported by the National Key Research and Development Program of China(No.2024YFE0206500)the National Science Foundation of China(Nos.22033009,22072156,22073104 and 22121002).
文摘The development of efficient Cu-based heterogeneous catalysts for CO_(2) hydrogenation to methanol has been an appealing subject.Inspired by the concept of inverse catalysts,a series of La_(2)O_(2)CO_(3)/Cu nanorod composites with varying Cu contents(denoted as LOC/Cu-x,where x stands for the mass ratio of La and Cu in the catalysts)were prepared by combining coprecipitation and calcination processes.Remarkable composition-dependence of catalytic activity and selectivity were observed when different LOC/Cu-x(x=0.1,0.2,0.5,1,3 and 5)were used to catalyze the CO_(2) hydrogenation.The predominant product shifted from methane to methanol with the increasing Cu content.The highest reaction rate(13.3 mmol·gCu^(-1)·h^(-1))and methanol selectivity(85.5%)were achieved when LOC/Cu-1 was tested at 200℃.The LOC was not active for the reaction,while the Cu itself displayed poor catalytic performance.The Cu–LOC interactions significantly affected the nature of the catalysts,including mutual electron transfer,crystal structure,morphology,porosity,surface Cu valence and capability of adsorbing the reactant gases,etc.,which account for the outstanding behavior of the LOC/Cu-1 catalyst.This work provides a new strategy for the design and optimization of Cu-based catalysts.
基金the National Natural Science Foundation of China(Grant Nos.22293015,22293012,and 22121002)the Research Funds of Happiness Flower ECNU(2020ST2203).
文摘Plastic waste is causing serious environmental problems. Developing efficient, cheap and stable catalytic routes to convert plastic waste into valuable products is of great importance for sustainable development, but remains to be a challenging task. Zeolites are cheap and stable, but they are usually not efficient for plastic conversion at a low temperature. Herein a series of microporous and mesoporous zeolites were used to study the influence of porosity and acidity of zeolite on catalytic activity for plastics conversion. It was observed that H-Beta zeolite was an efficient catalyst for cracking high-density polyethylene to gasoline at 240℃, and the products were almost C_(4)–C_(12) alkanes. The effect of porosity and acidity on catalytic performance of zeolites was evaluated, which clearly visualized the good performance of H-Beta due to high surface area, large channel system, large amount accessible acidic sites. This study provides very useful information for designing zeolites for efficient conversion of plastics.
基金supported by the National Natural Science Foundation of China(22273108,22073104,22293015,22033009,21890761,22121002,and 12275300)Beijing Natural Science Foundation(2222043)+1 种基金Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research(YSBR-050)the Innovation Program of the Institute of High Energy Physics,CAS(2023000034)。
基金supported by Beijing Natural Science Foundation(J210020)Hebei Natural Science Foundation(B2021208074)+2 种基金the National Natural Science Foundation of China(22002172,22003070,and 22121002)the National Key Research and Development Program of China(2020YFA0710203)Photon Science Center for Carbon Neutrality。
文摘The greenhouse gas CO_(2)emitted in the process of fossil fuels utilization can be decontaminated through carbon capture,utilization and storage technology(CCUS),which is an important pathway to close the carbon cycle and achieve carbon neutrality[1,2].In recent years,catalyzing CO_(2)reduction into high value-added C_(2+) products with high selectivity by electrochemical method has become a promising research area.Compared to C1products(such as CO,methane,formic acid and methanol),C_(2+)products(such as ethylene,ethanol,acetic acid and n-propanol)have higher energy density and economic value.At present,the main C1products of CO_(2)reduction reaction(CO_(2)RR),such as CO and formic acid,can achieve more than 90%selectivity and meet the industrial current density requirements of 300 mA cm^(-2)[3].However,the single selectivity and current density of C_(2+)products are still facing great challenges,mainly due to the complex reaction route,slow kinetic process,low catalyst activity and lack of exploration of mechanism,which make it difficult to meet the needs of large-scale production.
基金the National Natural Science Foundation of China(grant nos.22073104,22273108,22293015,22072156,and 22121002)the Beijing Natural Science Foundation(grant no.2222043)+1 种基金the CAS Project for Young Scientists in Basic Research(grant no.YSBR-050)the Innovation Program of the IHEP(grant no.2023000034)for their financial support of this research。
文摘The creation of universal strategies to affect the reaction route of the electroreduction of CO_(2) is critical.Here,we report the first work to introduce cations into diverse metals such as Cu,Bi,In,and Sn via the electroreduction of related metallic oxides in quaternary ammonium surfactant solutions.Compared to their physical adsorption,cations embedded into the electrodes have a more pronounced impact on the electrical field,which effectively influences the adsorption state of intermediates.With the increase of surface field,the hydrogen evolution reaction and*COOH route are significantly reduced,favouring the*OCHO pathway instead.As a result,hydrogen,CO,and C_(2+)products almost completely vanish at−0.5 V versus RHE in 0.1 M Na_(2)SO_(4)in an H-type cell after enough cations are embedded into the Cu electrode,and the faradaic efficiency of formate rises from 18.0%to 99.5%simultaneously.
基金the National Key Research and Development Program of China(grant no.2023YFA1507901)National Natural Science Foundation of China(grant nos.22003070,22293015,and 22121002).
文摘Electroreduction of carbon dioxide(CO_(2))into valuable chemicals and fuels is a promising strategy to mitigate energy and environmental problems.However,the poor selectivity and inadequate electrochemical stability prevent practical applications.In this work,we prepared ultrasmall copper(Cu)nanoparticles by using tannic acid as a complexing agent and stablizer.The ultrasmall Cu nanoparticles(3.4 nm)exhibited outstanding performance for CO_(2)electroreduction to CH_(4).The Faradaic efficiency of CH_(4)could reach up to 68%at-1.2 V versus reversible hydrogen electrode(RHE),with high current density of 475 mA·cm^(-2).The ultrasmall Cu nanoparticles could enhance the CO adsorption and H2O activation,resulting in the high selectivity of CH_(4).
基金supported by the National Natural Science Foundation of China(22293015,22203099,and 22121002)Strategic Priority Research Program(A)of the Chinese Academy of Sciences(XDA0390400)Photon Science Center for Carbon Neutrality。
文摘The electrochemical reduction of NO_(3)^(-)to NH_(3)holds promise for economic and environmental benefits,presenting an energyefficient alternative to the traditional Haber-Bosch method.However,challenges exist due to its sluggish kinetics,multiple intermediates,and various reaction pathways.In this study,Mn-doped-Cu catalyst was synthesized and employed for electrochemical NO_(3)^(-)-to-NH_(3)conversion.The doping of Mn into Cu resulted in exceptional performance,achieving a FE of 95.8%and an NH_(3)yield rate of 0.91 mol g^(-1)h^(-1)at-0.6 V in a neutral electrolyte at low NO_(3)^(-)concentration.Detailed experimental studies and theoretical calculations revealed that the Mn dopant enhanced the kinetic rate of NO_(2)~--to-NH_(3)and induced a distinct configuration of*NO.This alteration decreased the energy barrier of*NO-to-*NOH,consequently promoting the conversion of NO_(3)^(-)-to-NH_(3).
