CO2 hydrogenation to methanol is one of the most promising pathways for emission reduction.Unlike traditional synthesis gas(CO+H2)to methanol,a major challenge is that the activation of inert CO2 at high temp...CO2 hydrogenation to methanol is one of the most promising pathways for emission reduction.Unlike traditional synthesis gas(CO+H2)to methanol,a major challenge is that the activation of inert CO2 at high temperature will induce the reverse water-gas shift(RWGS)reaction to generate CO,thereby reducing the methanol yield.In this research,a novel catalyst Cu7Zn3Cr0.3 was synthesized by the carbon microsphere-assisted sol-gel method,which remarkably achieved a maximum methanol space-time yield of 345.1 g kg-1cath-1 under mild conditions(200℃,3.0 MPa,and 21600 m L gcat-1h-1).Characterizations combined with theoretical simulations show that Cr doping can affect the crystal structure of Zn O,resulting in the formation of more oxygen vacancies(OVs),and induce Cu to form a stable Cu0-OV-Cu+active center at the interface.This active structure efficiently enhances the adsorption and activation of CO2,while changing the reaction path to inhibit the production of CO.The results indicate that there is a clear linear relationship between the Cu+and OVs concentration and methanol yield,which could provide experimental references for the development of high-performance catalysts for CO2 methanol production.展开更多
Selective solar‑driven conversion of CO2into C2 hydrocarbons under aqueous conditions is a promising route toward carbon neutrality.However,C2 selectivity in water is severely constrained because the intrinsi...Selective solar‑driven conversion of CO2into C2 hydrocarbons under aqueous conditions is a promising route toward carbon neutrality.However,C2 selectivity in water is severely constrained because the intrinsically slow C–C coupling requires sustained electron flux to build up coupling‑relevant intermediates.This flux is readily depleted by the competing hydrogen evolution reaction and rapid carrier recombination.Here,we construct an in situ S‑scheme heterojunction of CuO islands on two‑dimensional(2D)N‑TiO2(CuO/N‑TiO2)via a one‑pot solvothermal strategy.The chemically anchored CuO islands on 2D N‑TiO2nanosheets create a compact,coherent interface that facilitates interfacial charge transfer.Compared with an ex situ assembled counterpart,the in situ heterojunction shows more efficient S‑scheme charge separation.In situ characterizations and theoretical calculations reveal that dynamically redox‑cycling Cu2+/Cu+sites are beneficial for C2H4formation,with Cu+sites favoring∗CO retention and Cu2+sites being more favorable for the subsequent asymmetric∗CO–∗CHO coupling step.Consequently,the as‑prepared catalyst delivers 17.5μmol g-1ethylene in 4 h with 94.6%selectivity and robust cycling stability.This work establishes an in situ S‑scheme heterojunction with oxide islands anchored on 2D nanosheets that integrates charge management with dynamic active sites for selective aqueous CO2‑to‑C2H4photoreduction.展开更多
The electrochemical carbon dioxide reduction reaction(CO2RR)to high value-added fuels or chemicals driven by the renewable energy is promising to alleviate global warming.However,the selective CO2reduction to C_...The electrochemical carbon dioxide reduction reaction(CO2RR)to high value-added fuels or chemicals driven by the renewable energy is promising to alleviate global warming.However,the selective CO2reduction to C2products remains challenge.Cu-based catalyst with the specific Cu0and Cu+sites is important to generate C2products.This work used nitrogen(N)to tune amounts of Cu0and Cu+sites in Cu2O catalysts and improve C2-product conversion.The controllable Cu0/Cu+ratio of Cu2O catalyst from 0.16 to 15.19 was achieved by adjusting the N doping amount using NH3/Ar plasma treatment.The major theme of this work was clarifying a volcano curve of the ethylene Faraday efficiency as a function of the Cu0/Cu+ratio.The optimal Cu0/Cu+ratio was determined as 0.43 for selective electroreduction CO2to ethylene.X-ray spectroscopy and density functional theory(DFT)calculations were employed to elucidate that the strong interaction between N and Cu increased the binding energy of N–Cu bond and stabilize Cu+,resulting in a 92.3%reduction in the potential energy change for∗CO-∗CO dimerization.This study is inspiring in designing high performance electrocatalysts for CO2conversion.展开更多
In this study,the effect of Cu2+on the cassiterite and calcite flotation using octanohydroxamic acid(OHA)as collector was investigated through flotation tests,solution reaction tests and calculation,zeta potential ...In this study,the effect of Cu2+on the cassiterite and calcite flotation using octanohydroxamic acid(OHA)as collector was investigated through flotation tests,solution reaction tests and calculation,zeta potential measurements,XPS analysis and residual reagent concentration measurements.Results indicated that Cu2+played an activation role on cassiterite flotation but a depression role on calcite flotation.The copper cations were adsorbed on the cassiterite surface by forming a Cu—O bond,and the pre-adsorbed copper cations and the OHA-Cu complexes promoted the adsorption of OHA on the cassiterite surface.Thus,cassiterite flotation was activated.The dissolved HCO3-in the calcite pulp underwent a double hydrolysis reaction with copper cations(Cu2+,CuOH+,Cu2(OH)22+and Cu3(OH)42+)to form CuCO3.Some copper cations were adsorbed on the calcite surface as well,but some adsorbed Cu2+on the calcite surface was desorbed by bonding with OHA,and most of OHA was consumed by Cu2+,basic copper carbonate and copper hydroxide.The residual OHA in the pulp was not sufficient for flotation,so calcite flotation was depressed.Finally,a model of the reaction mechanism of Cu2+and OHA on the cassiterite and calcite surfaces was established.展开更多
基金National Natural Science Foundation of China(22002135,22208283)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(20KJB480004)the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2022-K49)。
摘要CO2 hydrogenation to methanol is one of the most promising pathways for emission reduction.Unlike traditional synthesis gas(CO+H2)to methanol,a major challenge is that the activation of inert CO2 at high temperature will induce the reverse water-gas shift(RWGS)reaction to generate CO,thereby reducing the methanol yield.In this research,a novel catalyst Cu7Zn3Cr0.3 was synthesized by the carbon microsphere-assisted sol-gel method,which remarkably achieved a maximum methanol space-time yield of 345.1 g kg-1cath-1 under mild conditions(200℃,3.0 MPa,and 21600 m L gcat-1h-1).Characterizations combined with theoretical simulations show that Cr doping can affect the crystal structure of Zn O,resulting in the formation of more oxygen vacancies(OVs),and induce Cu to form a stable Cu0-OV-Cu+active center at the interface.This active structure efficiently enhances the adsorption and activation of CO2,while changing the reaction path to inhibit the production of CO.The results indicate that there is a clear linear relationship between the Cu+and OVs concentration and methanol yield,which could provide experimental references for the development of high-performance catalysts for CO2 methanol production.
基金financial support from the National University of Singapore(Chongqing)Research Institutethe Natural Science Foundation of Chongqing(No.CSTB2025NSCQ-GPX1115)。
摘要Selective solar‑driven conversion of CO2into C2 hydrocarbons under aqueous conditions is a promising route toward carbon neutrality.However,C2 selectivity in water is severely constrained because the intrinsically slow C–C coupling requires sustained electron flux to build up coupling‑relevant intermediates.This flux is readily depleted by the competing hydrogen evolution reaction and rapid carrier recombination.Here,we construct an in situ S‑scheme heterojunction of CuO islands on two‑dimensional(2D)N‑TiO2(CuO/N‑TiO2)via a one‑pot solvothermal strategy.The chemically anchored CuO islands on 2D N‑TiO2nanosheets create a compact,coherent interface that facilitates interfacial charge transfer.Compared with an ex situ assembled counterpart,the in situ heterojunction shows more efficient S‑scheme charge separation.In situ characterizations and theoretical calculations reveal that dynamically redox‑cycling Cu2+/Cu+sites are beneficial for C2H4formation,with Cu+sites favoring∗CO retention and Cu2+sites being more favorable for the subsequent asymmetric∗CO–∗CHO coupling step.Consequently,the as‑prepared catalyst delivers 17.5μmol g-1ethylene in 4 h with 94.6%selectivity and robust cycling stability.This work establishes an in situ S‑scheme heterojunction with oxide islands anchored on 2D nanosheets that integrates charge management with dynamic active sites for selective aqueous CO2‑to‑C2H4photoreduction.
基金supported by“Pioneer”and“Leading Goose”R&D Program of Zhejiang(Nos.2022C03146 and 2023C03017)the National Natural Science Foundation of China(Nos.U23A20677 and 22022610)+1 种基金Zhejiang Provincial Natural Science Foundation of China(No.LDT23E06015B06)the National Funded Postdoctoral Researcher Program of China(No.GZC20232363).
摘要The electrochemical carbon dioxide reduction reaction(CO2RR)to high value-added fuels or chemicals driven by the renewable energy is promising to alleviate global warming.However,the selective CO2reduction to C2products remains challenge.Cu-based catalyst with the specific Cu0and Cu+sites is important to generate C2products.This work used nitrogen(N)to tune amounts of Cu0and Cu+sites in Cu2O catalysts and improve C2-product conversion.The controllable Cu0/Cu+ratio of Cu2O catalyst from 0.16 to 15.19 was achieved by adjusting the N doping amount using NH3/Ar plasma treatment.The major theme of this work was clarifying a volcano curve of the ethylene Faraday efficiency as a function of the Cu0/Cu+ratio.The optimal Cu0/Cu+ratio was determined as 0.43 for selective electroreduction CO2to ethylene.X-ray spectroscopy and density functional theory(DFT)calculations were employed to elucidate that the strong interaction between N and Cu increased the binding energy of N–Cu bond and stabilize Cu+,resulting in a 92.3%reduction in the potential energy change for∗CO-∗CO dimerization.This study is inspiring in designing high performance electrocatalysts for CO2conversion.
基金Project(52074355)supported by the National Natural Science Foundation of ChinaProject(2023JJ10070)supported by the Outstanding Youth Scientist Foundation of Hunan Province,China。
摘要In this study,the effect of Cu2+on the cassiterite and calcite flotation using octanohydroxamic acid(OHA)as collector was investigated through flotation tests,solution reaction tests and calculation,zeta potential measurements,XPS analysis and residual reagent concentration measurements.Results indicated that Cu2+played an activation role on cassiterite flotation but a depression role on calcite flotation.The copper cations were adsorbed on the cassiterite surface by forming a Cu—O bond,and the pre-adsorbed copper cations and the OHA-Cu complexes promoted the adsorption of OHA on the cassiterite surface.Thus,cassiterite flotation was activated.The dissolved HCO3-in the calcite pulp underwent a double hydrolysis reaction with copper cations(Cu2+,CuOH+,Cu2(OH)22+and Cu3(OH)42+)to form CuCO3.Some copper cations were adsorbed on the calcite surface as well,but some adsorbed Cu2+on the calcite surface was desorbed by bonding with OHA,and most of OHA was consumed by Cu2+,basic copper carbonate and copper hydroxide.The residual OHA in the pulp was not sufficient for flotation,so calcite flotation was depressed.Finally,a model of the reaction mechanism of Cu2+and OHA on the cassiterite and calcite surfaces was established.