Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-dope...Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-doped cobalt molybdate(WDCMO)catalyst was synthesized for efficient and durable OER under neutral electrolyte.It is demonstrated that catalyst reconstruction is suppressed by W doping,which stabilizes the Co-O-Mo point-to-point connection in CoMoO_(4) architecture and stimulates to a lower valence state of active sites over the surface phase.Thereby,the surface structure maintains to avoid compound dissolution caused by over-oxidation during OER.Meanwhile,the WDCMO catalyst promotes charge transfer and optimizes*OH intermediate adsorption,which improves reaction kinetics and intrinsic activity.Consequently,the WDCMO electrode exhibits an overpotential of 302 mV at 10 mA cm^(-2) in neutral electrolyte with an improvement of 182 mV compared with CoMoO4 electrode.Furthermore,W doping significantly improves the electrode stability from 50 h to more than 320 h,with a suppressive potential attenuation from 2.82 to 0.29 mV h^(-1).This work will shed new light on designing rational electrocatalysts for neutral OER.展开更多
Reconstruction during the oxygen evolution reaction(OER)significantly transforms the geometric structure of transition metal compounds,leading to enhanced catalytic performance.However,the resulting structural disorde...Reconstruction during the oxygen evolution reaction(OER)significantly transforms the geometric structure of transition metal compounds,leading to enhanced catalytic performance.However,the resulting structural disorder complicates the development of accurate theoretical models.In this study,CoS2 is used as a model system to establish a framework for rationally modeling reconstructed OER catalysts based on density functional theory(DFT).In the reconstruction process,sulfur atoms are likely to be substituted by oxygen atoms,leading to the formation of the CoOOH phase.Based on the difference in reconstruction degree,we constructed three types of models:doping,heterostructure,and fully reconstructed,representing the reconstruction degree from minimal to full phase transition,respectively.Fully reconstructed models,which account for strain and vacancy effects,effectively simulate the unique coordination environments of reconstructed catalysts.Model e-CoOOH achieves a theoretical overpotential of 0.38 V,outperforming pristine CoOOH(0.56 V),demonstrating that the unique structural features resulting from reconstruction improve OER performance.The doping model and the heterostructure model are helpful to explain the electronic structure and performance transformation of the reconstruction process.This work provides a rational theoretical modeling approach,which is conducive to improving the reliability of the theoretical OER performance of the reconstructed catalyst.展开更多
Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies...Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies.Due to the existing infrastructure of global natural gas utilization and distribution,methane produced in such a green route attracts wide interests.However,limited success has been witnessed in the practical application of catalysts imparting satisfactory methane activity and selectivity.Herein,we report the fabrication of an atomically dispersed Co-Cu alloy through the reconstruction of trace-Co doped Cu metalorganic framework.This catalyst exhibits a methane Faradaic efficiency of 60%±1%with the corresponding partial current density of 303±5 mA·cm^(−2).Operando X-ray adsorption spectroscopy and attenuated-total-reflection surface enhanced infrared spectroscopy unravel that the introduction of atomically dispersed Co in Cu favors*CO protonation via enhancing surface water activation,and suppresses C−C coupling by reducing*CO coverage,thereby leading to high methane selectivity.展开更多
文摘Neutral oxygen evolution reaction(OER)is a crucial half-reaction for electrocatalytic chemical production under mild condition,but with limited development due to low activity and poor stability.Herein,a tungsten-doped cobalt molybdate(WDCMO)catalyst was synthesized for efficient and durable OER under neutral electrolyte.It is demonstrated that catalyst reconstruction is suppressed by W doping,which stabilizes the Co-O-Mo point-to-point connection in CoMoO_(4) architecture and stimulates to a lower valence state of active sites over the surface phase.Thereby,the surface structure maintains to avoid compound dissolution caused by over-oxidation during OER.Meanwhile,the WDCMO catalyst promotes charge transfer and optimizes*OH intermediate adsorption,which improves reaction kinetics and intrinsic activity.Consequently,the WDCMO electrode exhibits an overpotential of 302 mV at 10 mA cm^(-2) in neutral electrolyte with an improvement of 182 mV compared with CoMoO4 electrode.Furthermore,W doping significantly improves the electrode stability from 50 h to more than 320 h,with a suppressive potential attenuation from 2.82 to 0.29 mV h^(-1).This work will shed new light on designing rational electrocatalysts for neutral OER.
基金supported by the National Key Research and Development program(2022YFA1504000)the National Natural Science Foundation of China(22302101)+4 种基金the Fundamental Research Funds for the Central Universities(63185015)Shenzhen Science and Technology Program(JCYJ20210324121002007,JCYJ20230807151503007)Yunnan Provincial Science and Technology Project at Southwest United Graduate School(202402AO370001)China Postdoctoral Science Foundation(2022M721699)Guangdong Basic and Applied Basic Research Foundation(2024A1515010347).
文摘Reconstruction during the oxygen evolution reaction(OER)significantly transforms the geometric structure of transition metal compounds,leading to enhanced catalytic performance.However,the resulting structural disorder complicates the development of accurate theoretical models.In this study,CoS2 is used as a model system to establish a framework for rationally modeling reconstructed OER catalysts based on density functional theory(DFT).In the reconstruction process,sulfur atoms are likely to be substituted by oxygen atoms,leading to the formation of the CoOOH phase.Based on the difference in reconstruction degree,we constructed three types of models:doping,heterostructure,and fully reconstructed,representing the reconstruction degree from minimal to full phase transition,respectively.Fully reconstructed models,which account for strain and vacancy effects,effectively simulate the unique coordination environments of reconstructed catalysts.Model e-CoOOH achieves a theoretical overpotential of 0.38 V,outperforming pristine CoOOH(0.56 V),demonstrating that the unique structural features resulting from reconstruction improve OER performance.The doping model and the heterostructure model are helpful to explain the electronic structure and performance transformation of the reconstruction process.This work provides a rational theoretical modeling approach,which is conducive to improving the reliability of the theoretical OER performance of the reconstructed catalyst.
基金supported by the National Natural Science Foundation of China(Nos.22072101 and 22075193)the Natural Science Foundation of Jiangsu Province(No.BK20211306)+1 种基金Six Talent Peaks Project in Jiangsu Province(No.TD-XCL-006)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Electroreduction of carbon dioxide into value-added fuels or chemicals using renewable energy helps to effectively reduce carbon dioxide emission and alleviate the greenhouse effect while storing intermittent energies.Due to the existing infrastructure of global natural gas utilization and distribution,methane produced in such a green route attracts wide interests.However,limited success has been witnessed in the practical application of catalysts imparting satisfactory methane activity and selectivity.Herein,we report the fabrication of an atomically dispersed Co-Cu alloy through the reconstruction of trace-Co doped Cu metalorganic framework.This catalyst exhibits a methane Faradaic efficiency of 60%±1%with the corresponding partial current density of 303±5 mA·cm^(−2).Operando X-ray adsorption spectroscopy and attenuated-total-reflection surface enhanced infrared spectroscopy unravel that the introduction of atomically dispersed Co in Cu favors*CO protonation via enhancing surface water activation,and suppresses C−C coupling by reducing*CO coverage,thereby leading to high methane selectivity.
