Electrochemical reduction of CO2 to multi-carbon products(e.g.,C2+ ,ethene,ethanol,etc.)not only effectively decreases the CO2 concentration in atmosphere but also shows great potential economic benefits due ...Electrochemical reduction of CO2 to multi-carbon products(e.g.,C2+ ,ethene,ethanol,etc.)not only effectively decreases the CO2 concentration in atmosphere but also shows great potential economic benefits due to these exploitable value-added products.The Cu-based catalysts have caught much attention in CO2 electroreduction due to the good selectivity to hydrocarbons products.However,designing appropriate Cu-based catalysts is desirable to further improve the energy efficiency and selectivity of specific C2+ product.In this review,primary pathways of CO2 electroreduction to C2+ products are first discussed to summarize the key elementary steps of C2+ products formation.Subsequently,various strategies of catalytic activity regulation of Cu-based catalysts are classified into geometric and electronic structures modification based on the inner correlation between these strategies and the mechanism of C2+ products formation.The review ends with a cross-scale perspective that links the selectivity enhancement of a specific C2+ product and the target design of Cu-based catalysts.展开更多
In this study,the promotional effect of Ce and Nb doping on Cu/TiO2 catalyst for diethylamine catalytic degradation was investigated.The activity tests reveal that the Ce and Nb modification can facilitate the risi...In this study,the promotional effect of Ce and Nb doping on Cu/TiO2 catalyst for diethylamine catalytic degradation was investigated.The activity tests reveal that the Ce and Nb modification can facilitate the rising of mineralization rate and N2 selectivity during diethylamine degradation,achieving over 90%mineralization rate at 250-450°C,along with N2 selectivity exceeding 80% within 300-400°C.Characterization results show that the co-addition of Ce and Nb induces strong interactions with Cu species and increases surface Brønsted acid sites.Crucially,the enhanced redox capability derived from interactions guarantees good catalytic activity and mineralization rate.Additionally,the increased Brønsted acidity from Nb doping can suppress the formation of NCO(a)species,resulting in less generation of NOx from NCO(a)oxidation.Moreover,the enhanced Brønsted acidity can promote the internal SCR reaction,which also reduces the NOx emission.This work could offer valuable insights for designing catalysts with superior catalytic performance for amine-like volatile organic compounds(VOCs)degradation.展开更多
Comprehensive analysis of the connection be-tween surface metal species and the mechanism of hydrogen(H2)generation on TiO2provides important new information for the develop-ment of more effective catalysts for ...Comprehensive analysis of the connection be-tween surface metal species and the mechanism of hydrogen(H2)generation on TiO2provides important new information for the develop-ment of more effective catalysts for H2 produc-tion.We have systematically investigated the mechanism of catalytic H2 generation on the Cu10/TiO2,Au10/TiO2,Au8Cu2/TiO2and Cu1/Au8Cu2/TiO2surfaces using density func-tional theory.Our results demonstrate an O-Hδ+···Hδ−-M type transition state for H2 production,and the Au8Cu2(0.54 eV)bimetal-lic cluster catalyst exhibits more activity in comparison to the Cu10(0.63 eV)and Au10(0.88 eV)cluster catalysts on the TiO2surface.On the Cu1/Au8Cu2/TiO2surface,we found that Au8Cu2clusters act as electron donors,while Cu single atom acts as an electron acceptor.Therefore,the Au8Cu2bimetallic catalyst has a low energy barrier(0.58 eV)in the reductive reaction of H2 production in water,but Cu single atom as the catalytic center has a higher en-ergy barrier(1.49 eV).This implies that bimetallic catalysts may be able to catalyze the wa-ter dehydrogenation reaction more successfully,which would be important knowledge for comprehending and refining the photocatalytic H2 generation process.展开更多
The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO2 from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonizatio...The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO2 from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H2S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al2O3(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO2 hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H2S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO2 hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO2 Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnOx in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO2 hydrogenation to methanol,promoting the carbon emission reduction in steel industry.展开更多
Cu/ZrO2/SiO2 are efficient catalysts for the selective hydrogenation of CO2 to CH3OH. In order to understand the role of ZrO2 in these mixed-oxides based catalysts, in situ X-ray absorption spectroscopy has been carri...Cu/ZrO2/SiO2 are efficient catalysts for the selective hydrogenation of CO2 to CH3OH. In order to understand the role of ZrO2 in these mixed-oxides based catalysts, in situ X-ray absorption spectroscopy has been carried out on the Cu and Zr K-edge. Under reaction conditions, Cu remains metallic, while Zr is present in three types of coordination environment associated with 1) bulk ZrO2, 2) coordinatively saturated and 3) unsaturated Zr(Ⅳ) surface sites. The amount of coordinatively unsaturated Zr surface sites can be quantified by linear combination fit of reference X-Ray absorption near edge structure (XANES) spectra and its amount correlates with CH3OH formation rates, thus indicating the importance of Zr(Ⅳ) Lewis acid surface sites in driving the selectivity toward CH3OH. This finding is consistent with the proposed mechanism, where CO2 is hydrogenated at the interface between the Cu nanoparticles that split H2 and Zr(Ⅳ) surface sites that stabilizes reaction intermediates.展开更多
Cu/CeO2-ZrO2 catalysts for water-gas shift(WGS)reaction were prepared with co-precipitation method,and the influence of ZrO2 content on the catalytic structure and properties was investigated by the techniques of N2 p...Cu/CeO2-ZrO2 catalysts for water-gas shift(WGS)reaction were prepared with co-precipitation method,and the influence of ZrO2 content on the catalytic structure and properties was investigated by the techniques of N2 physical adsorption analysis,XRD and H2-TPR.The results indicate that the BET surface areas of the catalysts are increased in varying degrees due to the presence of ZrO2.With increasing ZrO2 content,the pore size distribution is centered on 1.9 nm.ZrO2 can efficiently restrain the growth of Cu crystal particles.The appropriate amount of ZrO2 in the Cu/CeO2 catalysts can help the catalyst keep better copper dispersion in the WGS reaction,which can lead to both higher catalytic activity and better thermal stability.When ZrO2 content is 10%(atom fraction),Cu/CeO2-Zr02 catalyst reaches a CO conversion rate of 73.7%at the reaction temperature of 200℃.展开更多
基金financially supported by the project Natural Science Foundation of Jiangxi Provincial(Grant Nos.20252BAC200212 and 20252BAC250027)the Fundamental Research Funds for the Cultivation of Early Career Young Scientific and Technological Talents of Jiangxi Province(Grant Nos.20252BEJ730203,20252BEJ730205,and 20224ACB203010)+2 种基金Doctor's Starting Research Foundation of Jiangxi University of Science and Technology(Grant No.205200100778)the National Natural Science Foundation of China(Grant Nos.22572077,22162012 and 22202089)the Natural Science Foundation of Jiangxi Province for Distinguished Young Scholars(Grant No.20224ACB213005)。
摘要Electrochemical reduction of CO2 to multi-carbon products(e.g.,C2+ ,ethene,ethanol,etc.)not only effectively decreases the CO2 concentration in atmosphere but also shows great potential economic benefits due to these exploitable value-added products.The Cu-based catalysts have caught much attention in CO2 electroreduction due to the good selectivity to hydrocarbons products.However,designing appropriate Cu-based catalysts is desirable to further improve the energy efficiency and selectivity of specific C2+ product.In this review,primary pathways of CO2 electroreduction to C2+ products are first discussed to summarize the key elementary steps of C2+ products formation.Subsequently,various strategies of catalytic activity regulation of Cu-based catalysts are classified into geometric and electronic structures modification based on the inner correlation between these strategies and the mechanism of C2+ products formation.The review ends with a cross-scale perspective that links the selectivity enhancement of a specific C2+ product and the target design of Cu-based catalysts.
基金Project supported by the National Natural Science Foundation of China (22076164,22276162,22306072)China Postdoctoral Science Foundation (2023M731441)Young Talent Fund of Jiaxing Science and Technology Project (2023AY40030)
摘要In this study,the promotional effect of Ce and Nb doping on Cu/TiO2 catalyst for diethylamine catalytic degradation was investigated.The activity tests reveal that the Ce and Nb modification can facilitate the rising of mineralization rate and N2 selectivity during diethylamine degradation,achieving over 90%mineralization rate at 250-450°C,along with N2 selectivity exceeding 80% within 300-400°C.Characterization results show that the co-addition of Ce and Nb induces strong interactions with Cu species and increases surface Brønsted acid sites.Crucially,the enhanced redox capability derived from interactions guarantees good catalytic activity and mineralization rate.Additionally,the increased Brønsted acidity from Nb doping can suppress the formation of NCO(a)species,resulting in less generation of NOx from NCO(a)oxidation.Moreover,the enhanced Brønsted acidity can promote the internal SCR reaction,which also reduces the NOx emission.This work could offer valuable insights for designing catalysts with superior catalytic performance for amine-like volatile organic compounds(VOCs)degradation.
基金supported by the National Natural Science Foundation of China(No.22473107)。
摘要Comprehensive analysis of the connection be-tween surface metal species and the mechanism of hydrogen(H2)generation on TiO2provides important new information for the develop-ment of more effective catalysts for H2 produc-tion.We have systematically investigated the mechanism of catalytic H2 generation on the Cu10/TiO2,Au10/TiO2,Au8Cu2/TiO2and Cu1/Au8Cu2/TiO2surfaces using density func-tional theory.Our results demonstrate an O-Hδ+···Hδ−-M type transition state for H2 production,and the Au8Cu2(0.54 eV)bimetal-lic cluster catalyst exhibits more activity in comparison to the Cu10(0.63 eV)and Au10(0.88 eV)cluster catalysts on the TiO2surface.On the Cu1/Au8Cu2/TiO2surface,we found that Au8Cu2clusters act as electron donors,while Cu single atom acts as an electron acceptor.Therefore,the Au8Cu2bimetallic catalyst has a low energy barrier(0.58 eV)in the reductive reaction of H2 production in water,but Cu single atom as the catalytic center has a higher en-ergy barrier(1.49 eV).This implies that bimetallic catalysts may be able to catalyze the wa-ter dehydrogenation reaction more successfully,which would be important knowledge for comprehending and refining the photocatalytic H2 generation process.
基金supported by the National Natural Science Foundation of China(Nos.22276060 and 21976059)Guangdong Basic and Applied Basic Research Foundation(No.2024A1515012636)China Scholarship Council Scholarship(No.201906155006)。
摘要The reduction of carbon emissions in the steel industry is a significant challenge,and utilizing CO2 from carbon intensive steel industry off-gases for methanol production is a promising strategy for decarbonization.However,steelwork off-gases typically contain various impurities,including H2S,which can deactivate commercial methanol synthesis catalysts,Cu/ZnO/Al2O3(CZA).Reverse water-gas shift(RWGS)reaction is the predominant side reaction in CO2 hydrogenation to methanol which can occur at ambient pressure,enabling the decouple of RWGS from methanol production at high pressure.Then,a series of activated CZA catalysts has been in-situ pretreated in 400 ppm H2S/Ar at 250℃and tested for both RWGS reaction at ambient pressure and CO2 hydrogenation to methanol at high pressure.An innovative decoupling strategy was employed to isolate the RWGS reaction from the methanol synthesis process,enabling the investigation of the evolution of active site structures and the poisoning mechanism through elemental analysis,X-ray Diffraction,X-ray Photoelectron Spectroscopy,Fourier Transform Infrared Spectroscopy,Temperature Programmed Reduction and CO2 Temperature Programmed Desorption.The results indicate that there are different dynamic migration behaviors of ZnOx in the two reaction systems,leading to different poisoning mechanisms.These interesting findings are beneficial to develop sulfur resistant and durable highly efficient catalysts for CO2 hydrogenation to methanol,promoting the carbon emission reduction in steel industry.
基金E.L.,K.L.,P.W.,and S.T.are supported by the SCCER-Heat and Energy Storage program
摘要Cu/ZrO2/SiO2 are efficient catalysts for the selective hydrogenation of CO2 to CH3OH. In order to understand the role of ZrO2 in these mixed-oxides based catalysts, in situ X-ray absorption spectroscopy has been carried out on the Cu and Zr K-edge. Under reaction conditions, Cu remains metallic, while Zr is present in three types of coordination environment associated with 1) bulk ZrO2, 2) coordinatively saturated and 3) unsaturated Zr(Ⅳ) surface sites. The amount of coordinatively unsaturated Zr surface sites can be quantified by linear combination fit of reference X-Ray absorption near edge structure (XANES) spectra and its amount correlates with CH3OH formation rates, thus indicating the importance of Zr(Ⅳ) Lewis acid surface sites in driving the selectivity toward CH3OH. This finding is consistent with the proposed mechanism, where CO2 is hydrogenated at the interface between the Cu nanoparticles that split H2 and Zr(Ⅳ) surface sites that stabilizes reaction intermediates.
基金supported by the National Natural Science Foundation of China(20271012)Project for Science and Technology ofFujian Province(2002H026)
摘要Cu/CeO2-ZrO2 catalysts for water-gas shift(WGS)reaction were prepared with co-precipitation method,and the influence of ZrO2 content on the catalytic structure and properties was investigated by the techniques of N2 physical adsorption analysis,XRD and H2-TPR.The results indicate that the BET surface areas of the catalysts are increased in varying degrees due to the presence of ZrO2.With increasing ZrO2 content,the pore size distribution is centered on 1.9 nm.ZrO2 can efficiently restrain the growth of Cu crystal particles.The appropriate amount of ZrO2 in the Cu/CeO2 catalysts can help the catalyst keep better copper dispersion in the WGS reaction,which can lead to both higher catalytic activity and better thermal stability.When ZrO2 content is 10%(atom fraction),Cu/CeO2-Zr02 catalyst reaches a CO conversion rate of 73.7%at the reaction temperature of 200℃.