Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we p...Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination temperature.Combined operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction effects.Further experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation mechanism.This work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.展开更多
Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)have gained significant attention due to their potential in thermoelectric(TE)applications.However,there has been much debating regarding their structural properties and phase diagram as a...Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)have gained significant attention due to their potential in thermoelectric(TE)applications.However,there has been much debating regarding their structural properties and phase diagram as a function of pressure,which is crucial for understanding of their TE properties.Here,we investigate a unified phase diagram of Mg_(3)(Bi,Sb)_(2) materials up to 40 GPa at room temperature using high-pressure X-ray diffraction.Two high-pressure phases with the structural transition succession of P3m1→C2/m→P21/n are observed,which is valid for all Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)compounds.We further explore the low-pressure phase P3m1 and report that alloying does not change the quasi-isotropic compression of the unit lattice parameters nor has effect on the anisotropic bond compressibility,as recently reported for the end-members.Our study presents a comprehensive picture of Mg_(3)Bi_(2–x)Sb_(x) as a function of pressure and chemical composition providing a solid foundation for the future experimental and theoretical studies searching for the most efficient TE compound in Mg_(3)(Bi,Sb)_(2).展开更多
Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging...Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging yet desirable.Herein,for the first time we reported that palladium-sulphur nanocrystals(Pd-S NCs)can be adopted as robust and universal catalysts,which can realize the efficient O_(2) conversion by three methods.As a result,Pd-S NCs exhibit an excellent selectivity(89.5%)to H_(2)O_(2)with high productivity(133.6 mol·kgcat^(−1)·h^(−1))in the direct synthesis,along with the significantly enhanced H_(2)O_(2)production activity and stability via electrocatalytic and photocatalytic syntheses.It is demonstrated that the isolated Pd sites can enhance the adsorption of O_(2) and inhibit its O–O bond dissociation,improving H_(2)O_(2)selectivity and reducing H_(2)O_(2)degradation.Further study confirms that the difference in surface atom composition and arrangement is the key factor for different ORR mechanisms on Pd NCs and Pd-S NCs.展开更多
Developing highly efficient,inexpensive catalysts for oxygen electrocatalysis in alkaline electrolytes(i.e.,the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER))is essential for constructing advanc...Developing highly efficient,inexpensive catalysts for oxygen electrocatalysis in alkaline electrolytes(i.e.,the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER))is essential for constructing advanced energy conversion techniques(such as electrolyzers,fuel cells,and metal–air batteries).Recent achievements in efficient noble metal-free ORR and OER catalysts make the replacement of conventional noble metal counterparts a realistic possibility.In particular,various electronic structure regulation strategies have been employed to endow these oxygen catalysts with attractive physicochemical properties and strong synergistic effects,providing significant fundamental understanding to advance in this direction.This review article summarizes recently developed electronic structure regulation strategies for three types of noble metal-free oxygen catalysts:transition metal compounds,single-atom catalysts,and metal-free catalysts.We begin by briefly presenting the basic ORR and OER reaction mechanisms,following this with an analysis of the fundamental relationship between electronic structure and intrinsic electrocatalytic activity for the three categories of catalysts.Subsequently,recent advances in electronic structure regulation strategies for noble metal-free ORR and OER catalysts are systematically dis-cussed.We conclude by summarizing the remaining challenges and presenting our outlook on the future for designing and synthesizing noble metal-free oxygen electrocatalysts.展开更多
As an emerging new type of battery chemistry,the anion shuttle battery(ASB),based on the shuttling and storage of anions,is considered a sustainable alternative to gigawatt-scale energy storage due to the associated r...As an emerging new type of battery chemistry,the anion shuttle battery(ASB),based on the shuttling and storage of anions,is considered a sustainable alternative to gigawatt-scale energy storage due to the associated resource abundance,low cost,high safety,and high energy density.Although significant progress has been achieved,practical applications of ASBs are still hindered by tough challenges,such as short lifetime,limited reversible capacity,and low Coulombic efficiency.Therefore,it is very necessary to design and explore new electrolyte systems with high electrochemical/chemical stability,sufficient compatibility towards electrodes,and excellent kinetics/reversibility for anion electrochemical reactions.Here,we review the recent achievements and main challenges in developing electrolytes for ASBs,which include solid,non-aqueous,and aqueous electrolytes.We mainly focus on the unique properties and basic principles of designing these electrolytes,and their various performance parameters.Perspectives on design strategies for ASB electrolytes are also presented,which could facilitate the development of advanced ASBs for grid-scale energy storage.展开更多
基金funded by the Australian Research Council Discovery Projects(DP160104835,Z.Shao)the Guangdong Basic and Applied Basic Research Foundation(2023A1515012878,D.Guan)+1 种基金the PolyU Distinguished Postdoctoral Fellowship Scheme(1-YWBU,D.Guan)the support from the Max Planck-POSTECH-Hsinchu Center for Complex Phase Materials。
文摘Material strain and reconstruction effects are critical for catalysis reactions,but current insights into operando strain effects during reaction and means to master catalyst reconstruction are still lacking.Here,we propose a facile thermal-induced phase-segregation strategy to simultaneously master material operando strain and reconstruction effects for enhanced oxygen-evolving reaction(OER).Specifically,self-assembled and controllable layered LiCoO_(2)phase and Co_(3)O_(4)spinel can be generated from pristine Li2Co_(2)O_(4)spinel via Li and O volatilization under different temperatures,realizing controllable proportions of two phases by calcination temperature.Combined operando and ex-situ characterizations reveal that obvious tensile strain along(003)plane appears on layered LixCoO_(2)phase during OER,while low-valence Co_(3)O_(4)phase transforms into high-valence CoOOHx,realizing simultaneous operando strain and reconstruction effects.Further experimental and computational investigations demonstrate that both strained LixCoO_(2)phase and reconstructed CoOOHxcompound contribute to the beneficial adsorption of important OH-reactants,while respective roles in activity and stability are uncovered by exploring their latticeoxygen participation mechanism.This work not only reveals material operando strain effects during OER,but also inaugurates a new thermal-induced phase-segregation strategy to artificially master material operando strain and reconstruction effects,which will enlighten rational material design for many potential reactions and applications.
基金W.Xu acknowledges the National Natural Science Foundation of China(Grants no.12075273)Y.Pan acknowledges the financial support from Alexander von Humboldt Foundation.S.Liu acknowledges National Natural Science Foundation of China under Grant No.51872133Shenzhen Key Program for Long-Term Academic Support Plan 20200925164021002.
文摘Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)have gained significant attention due to their potential in thermoelectric(TE)applications.However,there has been much debating regarding their structural properties and phase diagram as a function of pressure,which is crucial for understanding of their TE properties.Here,we investigate a unified phase diagram of Mg_(3)(Bi,Sb)_(2) materials up to 40 GPa at room temperature using high-pressure X-ray diffraction.Two high-pressure phases with the structural transition succession of P3m1→C2/m→P21/n are observed,which is valid for all Mg_(3)Bi_(2-x)Sb_(x)(0≤x≤2)compounds.We further explore the low-pressure phase P3m1 and report that alloying does not change the quasi-isotropic compression of the unit lattice parameters nor has effect on the anisotropic bond compressibility,as recently reported for the end-members.Our study presents a comprehensive picture of Mg_(3)Bi_(2–x)Sb_(x) as a function of pressure and chemical composition providing a solid foundation for the future experimental and theoretical studies searching for the most efficient TE compound in Mg_(3)(Bi,Sb)_(2).
基金the National Key R&D Program of China(Nos.2017YFA0208200 and 2016YFA0204100)the National Natural Science Foundation of China(No.22025108)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the start-up supports from Xiamen University.
文摘Although high-efficiency production of hydrogen peroxide(H_(2)O_(2))can be realized separately by means of direct,electrochemical,and photocatalytic synthesis,developing versatile catalysts is particularly challenging yet desirable.Herein,for the first time we reported that palladium-sulphur nanocrystals(Pd-S NCs)can be adopted as robust and universal catalysts,which can realize the efficient O_(2) conversion by three methods.As a result,Pd-S NCs exhibit an excellent selectivity(89.5%)to H_(2)O_(2)with high productivity(133.6 mol·kgcat^(−1)·h^(−1))in the direct synthesis,along with the significantly enhanced H_(2)O_(2)production activity and stability via electrocatalytic and photocatalytic syntheses.It is demonstrated that the isolated Pd sites can enhance the adsorption of O_(2) and inhibit its O–O bond dissociation,improving H_(2)O_(2)selectivity and reducing H_(2)O_(2)degradation.Further study confirms that the difference in surface atom composition and arrangement is the key factor for different ORR mechanisms on Pd NCs and Pd-S NCs.
基金supported by European Union's Horizon 2020 research and innovation programme(GrapheneCore3881603)Sachsisches Staatsministerium für Wissenschaft und Kunst(Sonderzuweisung zur Unterstützung profilbestimmender Struktureinheiten),German Research Foundation(DFG)within the Cluster of Excellence,and CRC 1415(grant no.417590517).
文摘Developing highly efficient,inexpensive catalysts for oxygen electrocatalysis in alkaline electrolytes(i.e.,the oxygen reduction reaction(ORR)and the oxygen evolution reaction(OER))is essential for constructing advanced energy conversion techniques(such as electrolyzers,fuel cells,and metal–air batteries).Recent achievements in efficient noble metal-free ORR and OER catalysts make the replacement of conventional noble metal counterparts a realistic possibility.In particular,various electronic structure regulation strategies have been employed to endow these oxygen catalysts with attractive physicochemical properties and strong synergistic effects,providing significant fundamental understanding to advance in this direction.This review article summarizes recently developed electronic structure regulation strategies for three types of noble metal-free oxygen catalysts:transition metal compounds,single-atom catalysts,and metal-free catalysts.We begin by briefly presenting the basic ORR and OER reaction mechanisms,following this with an analysis of the fundamental relationship between electronic structure and intrinsic electrocatalytic activity for the three categories of catalysts.Subsequently,recent advances in electronic structure regulation strategies for noble metal-free ORR and OER catalysts are systematically dis-cussed.We conclude by summarizing the remaining challenges and presenting our outlook on the future for designing and synthesizing noble metal-free oxygen electrocatalysts.
基金B.H.Li would like to thank the support provided by National Nature Science Foundation of China(No.51872157 and No.52072208)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01N111).
文摘As an emerging new type of battery chemistry,the anion shuttle battery(ASB),based on the shuttling and storage of anions,is considered a sustainable alternative to gigawatt-scale energy storage due to the associated resource abundance,low cost,high safety,and high energy density.Although significant progress has been achieved,practical applications of ASBs are still hindered by tough challenges,such as short lifetime,limited reversible capacity,and low Coulombic efficiency.Therefore,it is very necessary to design and explore new electrolyte systems with high electrochemical/chemical stability,sufficient compatibility towards electrodes,and excellent kinetics/reversibility for anion electrochemical reactions.Here,we review the recent achievements and main challenges in developing electrolytes for ASBs,which include solid,non-aqueous,and aqueous electrolytes.We mainly focus on the unique properties and basic principles of designing these electrolytes,and their various performance parameters.Perspectives on design strategies for ASB electrolytes are also presented,which could facilitate the development of advanced ASBs for grid-scale energy storage.
