The development of highly efficient and durable bifunctional catalysts with minimal precious metal usage is critical for advancing proton exchange membrane water electrolysis(PEMWE).We present an iridium-platinum nano...The development of highly efficient and durable bifunctional catalysts with minimal precious metal usage is critical for advancing proton exchange membrane water electrolysis(PEMWE).We present an iridium-platinum nanoalloy(IrPt)supported on lanthanum and nickel co-doped cobalt oxide,featuring a core-shell architecture with an amorphous IrPtOx shell and an IrPt core.This catalyst exhibits exceptional bifunctional activity for oxygen and hydrogen evolution reactions in acidic media,achieving 2 A cm^(-2)at 1.72 V in a PEMWE device with ultralow loadings of 0.075 mgIr cm^(-2)and 0.075 mgPt cm^(-2)at anode and cathode,respectively.It demonstrates outstanding durability,sustaining water splitting for over 646 h with a degradation rate of only 5μV h^(-1),outperforming state-of-the-art Ir-based catalysts.In situ X-ray absorption spectroscopy and density functional theory simulations reveal that the optimized charge redistribution between Ir and Pt,along with the IrPt core-IrPtOx shell structure,enhances performance.The Ir-O-Pt active sites enable a bi-nuclear mechanism for oxygen evolution reaction and a Volmer-Tafel mechanism for hydrogen evolution reaction,reducing kinetic barriers.Hierarchical porosity,abundant oxygen vacancies,and a high electrochemical surface area further improve electron and mass transfer.This work offers a cost-effective solution for green hydrogen production and advances the design of highperformance bifunctional catalysts for PEMWE.展开更多
Cluster satellites observed three successive outflowing ion beams on 28 March, 2001. It is generally accepted that these ion beams, composed of H^+, He^+, and O^+ ions, with three inverted-V structures in their energy...Cluster satellites observed three successive outflowing ion beams on 28 March, 2001. It is generally accepted that these ion beams, composed of H^+, He^+, and O^+ ions, with three inverted-V structures in their energy spectra, are produced by acceleration through U-shaped potential structures. By eliminating the background ion population and employing Maxwelling fitting, we find that ions coming from the center of the potential structure have higher temperature than those from the flanks. Higher temperature of O^+ and He+compared to that of H^+ indicates that heavy ions are preferentially heated; we further infer that the heating efficiencies of O^+ and He^+ ions differ between the center and edges of the U-shaped potential structures. Estimation based on pitch angle observations shows that heating may also occur at an altitude above the upper boundary of the auroral acceleration region(AAR), where these beams are generally thought to be formed.展开更多
Producing chemical fuels from sunlight enables a sustainable way for energy consumption.Among various solar fuel generation approaches,photocatalytic CO_(2) reduction has the advantages of simple structure,mild reacti...Producing chemical fuels from sunlight enables a sustainable way for energy consumption.Among various solar fuel generation approaches,photocatalytic CO_(2) reduction has the advantages of simple structure,mild reaction condition,directly reducing carbon emissions,etc.However,most of the current photocatalytic systems can only absorb the UV-visible spectrum of solar light.Therefore,finding a way to utilize infrared light in the photocatalytic system has attracted more and more attention.Here,a Z-scheme In_(2)S_(3)-TiO_(2) was constructed for CO_(2) reduction under concentrated natural sunlight.The infrared light was used to create a high-temperature environment for photocatalytic reactions.The evolution rates of H2,CO,and C2H5OH reached 262.2,73.9,and 27.56μmol・h^(-1)・g^(-1),respectively,with an overall solar to fuels efficiency of 0.002%.This work provides a composite photocatalyst towards the utilization of full solar light spectrum,and could promote the research on photocatalytic CO_(2) reduction.展开更多
基金supported by overseas Outstanding Youth Science Fund Project provided by National Natural Science Foundation of China(NSFC)under contract No.22Z990204807Natural Sciences—Basic Research Special Zone Program provided by shanghai government under contract No.22Z511203738+3 种基金Key Open Fund Project provided by Shaoxing New Energy and Molecular Engineering Research Institute,Shanghai Jiao Tong University under contract No.22H010103236Sinopec Natural Science research project provided by Sinopec research institute of petroleum processing under contract No.23H010100026support from National Science Foundation of China(22309113)Scientific and Technological Project of Yunnan Precious Metals Laboratory(YPML20240502029).
文摘The development of highly efficient and durable bifunctional catalysts with minimal precious metal usage is critical for advancing proton exchange membrane water electrolysis(PEMWE).We present an iridium-platinum nanoalloy(IrPt)supported on lanthanum and nickel co-doped cobalt oxide,featuring a core-shell architecture with an amorphous IrPtOx shell and an IrPt core.This catalyst exhibits exceptional bifunctional activity for oxygen and hydrogen evolution reactions in acidic media,achieving 2 A cm^(-2)at 1.72 V in a PEMWE device with ultralow loadings of 0.075 mgIr cm^(-2)and 0.075 mgPt cm^(-2)at anode and cathode,respectively.It demonstrates outstanding durability,sustaining water splitting for over 646 h with a degradation rate of only 5μV h^(-1),outperforming state-of-the-art Ir-based catalysts.In situ X-ray absorption spectroscopy and density functional theory simulations reveal that the optimized charge redistribution between Ir and Pt,along with the IrPt core-IrPtOx shell structure,enhances performance.The Ir-O-Pt active sites enable a bi-nuclear mechanism for oxygen evolution reaction and a Volmer-Tafel mechanism for hydrogen evolution reaction,reducing kinetic barriers.Hierarchical porosity,abundant oxygen vacancies,and a high electrochemical surface area further improve electron and mass transfer.This work offers a cost-effective solution for green hydrogen production and advances the design of highperformance bifunctional catalysts for PEMWE.
基金supported by the National Natural Science Foundation of China(grants 41474139,41731068,and 41704163)
文摘Cluster satellites observed three successive outflowing ion beams on 28 March, 2001. It is generally accepted that these ion beams, composed of H^+, He^+, and O^+ ions, with three inverted-V structures in their energy spectra, are produced by acceleration through U-shaped potential structures. By eliminating the background ion population and employing Maxwelling fitting, we find that ions coming from the center of the potential structure have higher temperature than those from the flanks. Higher temperature of O^+ and He+compared to that of H^+ indicates that heavy ions are preferentially heated; we further infer that the heating efficiencies of O^+ and He^+ ions differ between the center and edges of the U-shaped potential structures. Estimation based on pitch angle observations shows that heating may also occur at an altitude above the upper boundary of the auroral acceleration region(AAR), where these beams are generally thought to be formed.
基金This research was supported by the National Natural Science Foundation of China(51906199)China Postdoctoral Science Foundation Funded Project(2019M663703).
文摘Producing chemical fuels from sunlight enables a sustainable way for energy consumption.Among various solar fuel generation approaches,photocatalytic CO_(2) reduction has the advantages of simple structure,mild reaction condition,directly reducing carbon emissions,etc.However,most of the current photocatalytic systems can only absorb the UV-visible spectrum of solar light.Therefore,finding a way to utilize infrared light in the photocatalytic system has attracted more and more attention.Here,a Z-scheme In_(2)S_(3)-TiO_(2) was constructed for CO_(2) reduction under concentrated natural sunlight.The infrared light was used to create a high-temperature environment for photocatalytic reactions.The evolution rates of H2,CO,and C2H5OH reached 262.2,73.9,and 27.56μmol・h^(-1)・g^(-1),respectively,with an overall solar to fuels efficiency of 0.002%.This work provides a composite photocatalyst towards the utilization of full solar light spectrum,and could promote the research on photocatalytic CO_(2) reduction.
