Proton exchange membrane water electrolyzer(PEMWE)represents a highly promising technology for renewable hydrogen generation,urgently demanding low-cost,efficient,and robust anode oxygen evolution reaction(OER)electro...Proton exchange membrane water electrolyzer(PEMWE)represents a highly promising technology for renewable hydrogen generation,urgently demanding low-cost,efficient,and robust anode oxygen evolution reaction(OER)electrocatalysts in acidic media.Over the past decade(mainly from 2016 onwards),low-Ir/Ru perovskite oxides have emerged as promising candidate materials for acidic OER electrocatalysis owing to their flexible element compositions and crystal structures,which can evidently reduce the noble-metal content and meanwhile significantly promote electrocatalytic performance.In this review,the current research progress in low-Ir/Ru perovskite oxides for acidic OER electrocatalysis is comprehensively summarized.Initially,we present a brief introduction to general issues relevant to acidic OER catalyzed by low-Ir/Ru perovskite oxides,such as the actual active species,OER mechanisms,inverse activity-stability relationship,and performance evaluation metrics.Subsequently,we present a thorough overview of various low-Ir/Ru perovskite oxides for acidic OER electrocatalysis,including single perovskites,double perovskites,triple perovskites,quadruple perovskites,Ruddlesden-Popper perovskites,and other complex perovskite-derived oxides,with emphasis on the intrinsic factors contributing to their exceptional performance and structure-property-performance correlation.Finally,remaining challenges and some promising insights to inspire future studies in this exciting field are provided.展开更多
The sluggish kinetics of the oxygen evolution reaction(OER)process impedes the exploration of green hydrogen via water splitting.Herein,we design and synthesize vanadium-doped CoSn(OH)_(6)perovskite hydroxide catalyst...The sluggish kinetics of the oxygen evolution reaction(OER)process impedes the exploration of green hydrogen via water splitting.Herein,we design and synthesize vanadium-doped CoSn(OH)_(6)perovskite hydroxide catalysts by Fe^(3+)etching during the hydrothermal and chemical deposition process.The as-prepared CoVSn(OH)_(6)@CoVSnFe(OH)_(x)-4 catalyst exhibits a lowoverpotential of 225 mV at 10 mA·cm^(-2)with a Tafel slope of 30.47 mV·dec^(-1).An overall water splitting electrolyzer(CoVSn(OH)_(6)@CoVSnFe(OH)_(x)-4‖Pt/C)is constructed,delivering a voltage of 1.48 V at a current density of10 mA·cm^(-2)with excellent durability.The dynamic phase evolution during the OER process is revealed by in situ Raman and XPS measurement,which represents that the introduced V and Fe ions facilitate the formation of active CoOOH as well as modify the electronic structure of the catalyst.Density functional theory(DFT)calculations further evidence that V and Fe introduction optimize the adsorption energies of oxygen intermediates*OH and*O,respectively,thereby enabling a synergistic optimization of the multi-step OER process and advancing electrocatalytic performance.展开更多
ABO_(3)-type perovskite oxides(e.g.,LaCoO_(3))with flexible and adjustable A-and B-sites are ideal model catalysts to unravel the relationship between the electronic structure and electrocatalytic activity(e.g.,oxygen...ABO_(3)-type perovskite oxides(e.g.,LaCoO_(3))with flexible and adjustable A-and B-sites are ideal model catalysts to unravel the relationship between the electronic structure and electrocatalytic activity(e.g.,oxygen reduction/evolution reactions,ORR/OER).It has been well understood in our recent work that the secondary metal dopant at B-site(e.g.,Mn in LaMn_(x)Co_(1-x)O_(3))can regulate the electronic structure and improve the ORR/OER activity.In this work,the Mn-Ni pairs are employed as the dual dopant in LaMn_(x)Ni_(y)Co_(z)O_(3)(x+y+z=1)catalysts toward bifunctional ORR and OER.The structure-property relationships between the triple metal B-site(Mn,Ni and Co)and the electrochemical performance are particularly investigated.Compared to the individual Mn doping(e.g.,LaMnCoO3(Mn:Co=1:3)catalyst),the dual Mn-Ni doping significantly improves the ORR mass activity@0.8 V by 1.54 times;meanwhile,the OER overpotential@10 mA cm^(-2) is reduced from 420 to 370 mV,and the OER current density at 1.55 V is increased by 2.43 times.Reasonably,the potential gap between EDRR@-1 mA cm^(-2) and EDER@10 mA cm^(-2) is achieved as only 0.76 V by using the optimal LaMn_(x)Ni_(y)Co_(z)O_(3)(x:y:z=1:2:3)catalyst.It is revealed that the dual Mn-Ni dopant efficiently optimizes electron structures of the LaMnNiCoO_(3)(1:2:3)catalyst,which not only decreases the e_(g) orbital electron number,but also modulates the O 2 p-band closer to the Femi level,accounting for the enhanced bifunctional activity.展开更多
Oxygen evolution reaction(OER)is a kinetically harsh four-electron anode reaction that requires a large overpotential to provide current and is of great importance in renewable electrochemical technique.Ir/Rubased per...Oxygen evolution reaction(OER)is a kinetically harsh four-electron anode reaction that requires a large overpotential to provide current and is of great importance in renewable electrochemical technique.Ir/Rubased perovskite oxides hold great significance for application as OER electrocatalysts,due to that their multimetal-oxide forms can reduce the use of noble metals,and their compositional tunability can modulate the electronic structure and optimize OER performance.However,high operating potentials and corrosive environments pose a serious challenge to the development of durable Ir-based and Ru-based perovskite electrocatalysts.Tremendous efforts have been dedicated to improving the Ir/Ru-based perovskite activity to enhance the efficiency;however,progress in improving the durability of Ir/Ru-based perovskite electrocatalysts has been rather limited.In this review,the recent research progress of Ir/Ru-based perovskites is reviewed from the perspective of heteroatom doping,structural modulation,and formation of heterostructures.The dissolution mechanism studies of Ir/Ru and experimental attempts to improve the durability of Ir/Ru-based perovskite electrocatalysts are discussed.Challenges and outlooks for further developing Ru-and Irbased perovskite oxygen electrocatalysts are also presented.展开更多
Development of cost-effective and highly active oxygen evolution catalysts operating well in acidic media is a critical challenge in proton exchange membrane water electrolysis.Herein,we present a class of iridium-bas...Development of cost-effective and highly active oxygen evolution catalysts operating well in acidic media is a critical challenge in proton exchange membrane water electrolysis.Herein,we present a class of iridium-based 12L-perovskites(Ba4MIr3O12;M=Pr,Bi,Nb)as novel low-iridium electrocatalysts for oxygen evolution reaction under acidic conditions.These 12L-perovskites contain trinuclear face-shared Ir O6octahedral strings—unique subunits that are not found in the previously-reported iridium-based electrocatalysts.The catalytic activities of 12L-perovskites(Ba4MIr3O12)are found to be related to the location of O 2p-band center,which is influenced by the B-site nonprecious element(i.e.,Pr,Bi or Nb).Our experimental results show that Ba4PrIr3O12is the most active electrocatalyst among the materials we synthesize,and contains 55%less iridium than the benchmark catalyst IrO2,while exhibiting higher catalytic activity.In the presence of Ba4PrIr3O12,transient leaching process of Ba and Pr takes place during electrochemical process,contributing to the surface reconstruction of the pristine catalysts.Further experimental results reveal that the formation of under-coordinated Ir Ox-rich surface and easier generation of active intermediate IrVare mainly responsible for the good activity of Ba4PrIr3O12.展开更多
Effective electrocatalysis is crucial for enhancing the efficiency of water splitting to obtain clean fuels.Herein,we report a system of interesting and high-performance Sr-doped perovskite electrocatalysts with porou...Effective electrocatalysis is crucial for enhancing the efficiency of water splitting to obtain clean fuels.Herein,we report a system of interesting and high-performance Sr-doped perovskite electrocatalysts with porous structures,obtained via a facile molten salt method and applied in the oxygen evolution reaction(OER).With increasing the Sr content,the valence states of Co and Fe ions do not clearly increase,according to the Co-L2,3 and Fe-L2,3 as well as the Co-K and the Fe-K X-ray absorption spectroscopy,whereas doped holes are clearly observed in the 0-K edge.High-resolution transmission electron microscopy indicates the appearance of an amorphous layer after the electrochemical reaction.We conclude that the formation of the amorphous layer at the surface,induced by Sr doping,is crucial for achieving high OER activity,and we offer insights into the self-reconstruction of the OER catalyst.展开更多
The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-co...The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-contained 6H-perovskites with a formula of Ba3LnIr2〇9(Ln=lanthanides)are investigated as oxygen evolution electrocatalysts,whose active subunits(i.e.,face-sharing Ir〇6 dimers)can be regulated by the lanthanides in terms of catalytic activity.By using density functional theory(DFT)calculations,we establish the theoretical trend in activity for Ba3LnIr2〇96H-perovskites,the activity of which is correlated with the difference of adsorption free energy(△G〇-△Goh)between O*and OH*reaction intermediates.We further establish a volcano curve between△Go—△Goh and the calculated 0 p-band center Among the Ba3LnIr2〇96H-perovskites,Ba3Lalr2〇9 locates at the peak of volcano curve,and correspondingly is the most active electrocatalyst due to the optimal 0 p-band property.展开更多
The oxygen evolution reaction (OER) dominates the efficiency of electrocatalytic water splitting owing to its sluggish kinetics.Perovskite oxides (ABO_(3)) have emerged as promising candidates to accelerate the OER pr...The oxygen evolution reaction (OER) dominates the efficiency of electrocatalytic water splitting owing to its sluggish kinetics.Perovskite oxides (ABO_(3)) have emerged as promising candidates to accelerate the OER process owing to their high intrinsic activities and tailorable properties.Fe ions in perovskite oxides have been proved to be a highly catalytic element for OER,while some Fe-based perovskites such as SrTi_(0.8)Fe_(0.2)O_(3-δ)(STF) and La_(0.66)Ti_(0.8)Fe_(0.2)O_(3-δ)(LTF) exhibit inferior OER activity.Yet the essential reason is still unclear and the effective method to promote the activity of such perovskite is also lacking.Herein,an in-situ exsolution strategy was proposed to boost the OER by migrating Fe from the bulk to the surface.Significantly enhanced OER activity was achieved on STF and LTF perovskites with surfacedecorated oxygen vacancies and Fe nanoparticles.In addition,theoretical calculation confirmed that the oxygen vacancies and Fe nanoparticle on surface could lower the overpotential of OER by facilitating the adsorption of OH^(-).From this study,migration of the active elements in perovskite is found to be an effective strategy to increase the quantity and activity of active sites,providing new insights and understanding for designing efficient OER catalysts.展开更多
The oxygen evolution reaction(OER) plays a crucial role in many electrochemical energy technologies,and creating multiple beneficial factors for OER catalysis is desirable for achieving high catalytic efficiency.Here,...The oxygen evolution reaction(OER) plays a crucial role in many electrochemical energy technologies,and creating multiple beneficial factors for OER catalysis is desirable for achieving high catalytic efficiency.Here,we highlight a new halogen-chlorine(Cl)-anion doping strategy to boost the OER activity of perovskite oxides.As a proof-of-concept,proper Cl doping at the oxygen site of LaFeO3(LFO) perovskite can induce multiple favorable characteristics for catalyzing the OER,including rich oxygen vacancies,increased electrical conductivity and enhanced Fe-O covalency.Benefiting from these factors,the LaFeO2.9-δCl0.1(LFOCl) perovskite displays significant intrinsic activity enhancement by a factor of around three relative to its parent LFO.This work uncovers the effect of Cl-anion doping in perovskites on promoting OER performance and paves a new way to design highly efficient electrocatalysts.展开更多
Perovskite LaCoO_(3) is being increasingly explored as an effective low-cost electrocatalyst for the oxygen evolution reaction(OER).Sr doping in LaCoO_(3)(La1-xSrxCoO_(3))has been found to substantially increase its c...Perovskite LaCoO_(3) is being increasingly explored as an effective low-cost electrocatalyst for the oxygen evolution reaction(OER).Sr doping in LaCoO_(3)(La1-xSrxCoO_(3))has been found to substantially increase its catalytic activity.In this work,we report a detailed study on the evolution of the electronic structure of La1-xSrxCoO_(3) with 0≤x≤1 and its correlation with electrocatalytic activity for the OER.A combination of X-ray photoemission spectroscopy(XPS)and X-ray absorption spectroscopy(XAS)was used to unravel the electronic density of states(DOS)near the Fermi level(EF),which provide insights into the key electronic structure features for the enhanced OER catalytic activity.Detailed analysis on the Co L-edge XAS suggest that LaCoO_(3) has a low spin state with t_(2g)^(6) e_(g)^(0) configuration at room temperature.This implies that the high OER catalytic activity of LaCoO_(3) should not be rationalized by the occupancy of eg=1 descriptor.Substituting Sr^(2+) for La^(3+) in LaCoO_(3) induces Co4+oxidation states and effectively dopes hole states into the top of valence band.A semiconductor-to-metal transition is observed for x>0.2,due to the holeinduced electronic DOS at the EF and increased hybridization between Co 3 d and O 2 p.Such an electronic modulation enhances the surface adsorption of the*OH intermediate and reduces the energy barrier for interfacial charge transfer,thus improving the OER catalytic activity in La_(1-x)Sr_(x)CoO_(3).In addition,we found that the La_(1-x)Sr_(x)CoO_(3) surface undergoes amorphization after certain period of OER measurement,leading to a partial deactivation of the electrocatalyst.High Sr doping levels accelerated the amorphization process.展开更多
The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity.Conventional ...The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity.Conventional methods for A-site substitution typically involve prolonged high-temperature processes.While these processes promote the development of unique nanostructures with highly exposed active sites,they often result in the uncontrolled configuration of introduced elements.Herein,we present a novel approach for synthesizing two-dimensional(2D)porous GdFeO_(3) perovskite with A-site strontium(Sr)substitution utilizing microwave shock method.This technique enables precise control of the Sr content and simultaneous construction of 2D porous structures in one step,capitalizing on the advantages of rapid heating and cooling(temperature~1100 K,rate~70 K s^(-1)).The active sites of this oxygen-rich defect structure can be clearly revealed through the simulation of the electronic configuration and the comprehensive analysis of the crystal structure.For electrocatalytic oxygen evolution reaction application,the synthesized 2D porous Gd_(0.8)Sr_(0.2)FeO_(3) electrocatalyst exhibits an exceptional overpotential of 294 mV at a current density of 10 mA cm^(-2)and a small Tafel slope of 55.85 mV dec^(-1)in alkaline electrolytes.This study offers a fresh perspective on designing crystal configurations and the construction of nanostructures in perovskite.展开更多
Cobalt-rich perovskite oxides play a paramount role in catalyzing oxygen evolution reaction(OER)on account of their acceptable intrinsic activity but are still challenging due to the high costs and undesired stability...Cobalt-rich perovskite oxides play a paramount role in catalyzing oxygen evolution reaction(OER)on account of their acceptable intrinsic activity but are still challenging due to the high costs and undesired stability.In response to the defects,herein,the Mg-incorporated perovskite cobaltite SrCo_(0.6)Fe_(0.3M)g_(0.1)O_(3-δ)(SCFM-0.1)is proposed as a novel earth-abundant and durable OER electrocatalyst.A well-consolidated cubic-symmetry structure and more active oxygen intermediates are enabled upon Mg substitution.Hence,the optimized SCFM-0.1 perovskite oxide achieves prominent OER electrocatalytic performance,that is,a low overpotential of only 320 mV at 10 mA cm^(-2),a small Tafel slope of 65 mV dec^(-1),as well as an outstanding durability within 20 h,substantially outperforming that of the pristine SrCo_(0.7)Fe_(0.3)O_(3-δ)and benchmark Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)and IrO_(2) catalysts.The strong pHdependent behavior associated with lattice oxygen activation mechanism for SCFM-0.1 catalyst is also confirmed.This work paves a unique avenue to develop cost-effective and robust perovskite cobaltites for efficient OER electrocatalysis.展开更多
Water splitting is important to the conversion and storage of renewable energy,but slow kinetics of the oxygen evolution reaction(OER)greatly limits its utility.Here,under visible light illumination,the p-n WO_(3)/SnS...Water splitting is important to the conversion and storage of renewable energy,but slow kinetics of the oxygen evolution reaction(OER)greatly limits its utility.Here,under visible light illumination,the p-n WO_(3)/SnSe_(2)(WS)heterojunction significantly activates OER catalysis of CoFe-layered double hydroxide(CF)/carbon nanotubes(CNTs).Specifically,the catalyst achieves an overpotential of 224 mV at 10 mA cm^(-2)and a small Tafel slope of 47 mV dec^(-1),superior to RuO_(2)and most previously reported transition metal-based OER catalysts.The p-n WS heterojunction shows strong light absorption to produce photogenerated carriers.The photogenerated holes are trapped by CF to suppresses the charge recombination and facilitate charge transfer,which accelerates OER kinetics and boost the activity for the OER.This work highlights the possibility of using heterojunctions to activate OER catalysis and advances the design of energy-efficient catalysts for water oxidation systems using solar energy.展开更多
Metal exsolution engineering has been regarded as a promising strategy for activating intrinsically inert perovskite oxide catalysts toward efficient oxygen evolution reaction.Traditional metal exsolution processes on...Metal exsolution engineering has been regarded as a promising strategy for activating intrinsically inert perovskite oxide catalysts toward efficient oxygen evolution reaction.Traditional metal exsolution processes on perovskites are often achieved by using the reducing hydrogen gas;however,this is not effective for the relatively stable phase,such as Ruddlesden-Popper perovskite oxides.To address this issue,triphenylphosphine is proposed to be a reduction promotor for accelerating the reduction and migration of the target metal atoms,aiming to achieve the effective exsolution of metallic species from Ruddlesden-Popper-type parent perovskites.Upon oxygen evolution reaction,these exsolved metallic aggregates are reconstructed into oxyhydroxides as the real active centers.After further modification by lowpercentage iridium oxide nanoclusters,the optimal catalyst delivered an overpotential as low as 305 mV for generating the density of 10 mA cm^(-2),outperforming these reported noble metal-containing perovskite-based alkaline oxygen evolution reaction electrocatalysts.This work provides a potential approach to activate catalytically inert oxides through promoting surface metal exsolution and explores a novel class of Ruddlesden-Poppertype oxides for electrocatalytic applications.展开更多
We report a facile way to prepare sulfur(S) doped Ni4/5 Fe1/5-layered double hydroxide(LDH) electrocatalysts for oxygen evolution reaction(OER). The influence of S doping amount on the OER activity of the resulted Ni ...We report a facile way to prepare sulfur(S) doped Ni4/5 Fe1/5-layered double hydroxide(LDH) electrocatalysts for oxygen evolution reaction(OER). The influence of S doping amount on the OER activity of the resulted Ni Fe-LDHs was studied and the optimal surface S content was ca. 0.43 at%. The developed S-doped Ni Fe-LDH exhibits excellent OER catalyst activity in 1.0 M KOH with overpotential of only 257 m V at the current density of 10 m A cm^-2. Moreover, the catalyst could maintain high activity after 30 h stability test. The high activity of the S-doped Ni Fe-LDH catalysts may originate from the synergistic effect between S and the Fe sites. This work provides a simple but efficient way to improve the OER performance of transition metal oxides/(oxy)hydroxides.展开更多
The primary challenge in rechargeable Zn-air batteries lies in developing a catalyst capable of simultaneously improving performance for oxygen reduction reaction(ORR)during discharge and oxygen evolution reaction(OER...The primary challenge in rechargeable Zn-air batteries lies in developing a catalyst capable of simultaneously improving performance for oxygen reduction reaction(ORR)during discharge and oxygen evolution reaction(OER)during charge.Engineering spin configuration is essential for enhancing the intrinsic bifunctional activity and stability of spinel Co_(3)O_(4).Herein,Cr^(3+)is doped into Co_(3)O_(4),inducing directional distortion of CoO_6 octahedron to modify crystal field splitting energy,pushing Co_(Oh)toward intermediate-spin(IS)configuration(t_(2g)^(5)e_(g^(1)))with optimized eg occupancy of 1.04.As a result,9%Cr-Co_(3)O_(4)demonstrates an excellent bifunctional activity and remarkable rechargeable Zn-air battery performance that even outperforms Pt/C+RuO_(2).Density functional theory(DFT)studies reveal that IS Co_(Oh)not only regulates the adsorption energy of ORR/OER species but also transform the O_(2)adsorption configuration from end-on to Griffith configuration,thus modifies the mechanisms of both ORR and OER process and optimize bifunctional activity and selectivity.This work provides mechanistic insight into the spin origin of ORR/OER catalysis and highlights a promising strategy for developing robust bifunctional electrocatalysts.展开更多
Transition metal phosphides exhibit excellent efficiency in the oxygen evolution reaction under alkaline conditions,and they have garnered widespread recognition.Currently,most studies have focused on the evolution an...Transition metal phosphides exhibit excellent efficiency in the oxygen evolution reaction under alkaline conditions,and they have garnered widespread recognition.Currently,most studies have focused on the evolution and role of metal cations in the oxygen evolution reaction process,while attention to phosphorus elements is relatively scarce.Actually,phosphides possess unique properties that distinguish them from other metal compounds,and the role of phosphorus in them cannot be ignored.This study used nickel phosphide(Ni_(2)P)as a model catalyst to reveal the reconstruction and dynamic behavior of anions under alkaline conditions through cyclic voltammetry.The results indicate that as the cycle progresses,surface phosphides are converted into active oxyhydroxides.It is worth noting that the presence of the P element accelerates the rapid completion of the reconstruction process but also exhibits triple synergistic functions.First,the internal phosphorus nuclei of the active layer act as conductive scaffolds,effectively enhancing the efficiency of electron conduction.Second,the oxygen-containing anions formed in situ on metal hydroxides optimize the adsorption of reaction intermediates.Finally,the phosphorus atoms dissolved in the electrolyte suppress nickel loss,improve stability,and increase the electrochemical activity specific surface area,exposing more active sites.This study elucidates the oxygen evolution reaction mechanism of phosphides from a novel perspective,enhancing comprehension of surface reconstruction phenomena and the characteristics of active sites,guiding the rational design of phosphide pre-catalysts.展开更多
Oxygen evolution reaction(OER)is a key step in hydrogen production by water electrolysis technology.How-ever,developing efficient,stable,and low-cost OER electrocatalysts is still challenging.This article presents the...Oxygen evolution reaction(OER)is a key step in hydrogen production by water electrolysis technology.How-ever,developing efficient,stable,and low-cost OER electrocatalysts is still challenging.This article presents the preparation of a series of novel copper iridium nanocatalysts with heterostructures and low iridium content for OER.The electrochemical tests revealed higher OER of Cu@Ir_(0.3) catalyst under acidic conditions with a generated current density of 10 mA/cm^(2) at only 284 mV overpotential.The corresponding OER mass activity was estimated to be 1.057 A/mgIr,a value 8.39-fold higher than that of the commercial IrO_(2).After 50 h of endurance testing,the Cu@Ir_(0.3) catalyst preserved excellent catalytic activity with a negligible rise in overpotential and maintained a good heterostructures.Cu@Ir_(0.3) The excellent OER activity can be attributed to its heterostructure,as con-firmed by density functional theory(DFT)calculations,indicating that Cu@Ir The coupling between isoquanta causes charge redistribution,optimizing the adsorption energy of unsaturated Ir sites for oxygen intermediates and reducing the energy barrier of OER free energy determining the rate step.In summary,this method provides a new approach for designing efficient,stable,and low iridium content OER catalysts.展开更多
Self-supported,hot-pressed FeNiCoCuMo high-entropy alloy(HEA)electrodes were fabricated and characterized by X-ray diffraction(XRD),high-resolution transmission electron microscopy(HR-TEM),and energy dispersive spectr...Self-supported,hot-pressed FeNiCoCuMo high-entropy alloy(HEA)electrodes were fabricated and characterized by X-ray diffraction(XRD),high-resolution transmission electron microscopy(HR-TEM),and energy dispersive spectroscopy(EDS),confirming a face-centered cubic(FCC)matrix with minor body-centered cubic(BCC)phase(~1wt%).We map the redox behavior of the individual constituents(Fe,Ni,Co,Cu,and Mo)and compare it with HEA to reveal solid-solution synergy(“cocktail effect”).Electrochemistry(cyclic voltammetry(CV)/linear sweep voltammetry(LSV)/Tafel in 1.0 M KOH)and X-ray photoelectron spectroscopy(XPS)show broadened redox features for HEA and Ni/Co-rich(oxy)hydroxide signatures with MoOx contributions.Triplicate electrodes(M1–M3)deliver an average overpotential of 370 m V at 10mA·cm^(-2)and a Tafel slope of 78 mV·dec^(-1),outperforming monometallic references and remaining competitive with the literature-reported RuO_(2).Chronopotentiometry 100 h evidence stable operation;post-mortem XRD indicates a thin reconstructed surface while the bulk remains FCC-dominated.Density functional theory(DFT)supports broadened electronic states near the Fermi level and enhanced charge transfer.Overall,structure and computation link compositional disorder,surface reconstruction,and oxygen evolution reaction(OER)kinetics in a robust anode for alkaline oxygen evolution.展开更多
Electrocatalytic oxygen reduction and evolution reactions are involved in new energy conversion and storage technologies,such as various fuel cells and metal-air batteries and also water splitting devices[1,2].However...Electrocatalytic oxygen reduction and evolution reactions are involved in new energy conversion and storage technologies,such as various fuel cells and metal-air batteries and also water splitting devices[1,2].However,both reactions are very slow in kinetics,and thus catalysts are required[3,4].展开更多
基金supported by the Natural Science Foundation for Young Scholars of Jiangsu Province(No.BK20220879)the National Natural Science Foundation of China(No.22209072 and No.22479075)+1 种基金the Open Research Fund of Guangdong Advanced Carbon Materials Co.,Ltd(No.Kargen-2024B0801)the Jiangsu Specially-Appointed Professors and National Natural Science Fund of China for Excellent Young Scientists Fund Program(Overseas)。
文摘Proton exchange membrane water electrolyzer(PEMWE)represents a highly promising technology for renewable hydrogen generation,urgently demanding low-cost,efficient,and robust anode oxygen evolution reaction(OER)electrocatalysts in acidic media.Over the past decade(mainly from 2016 onwards),low-Ir/Ru perovskite oxides have emerged as promising candidate materials for acidic OER electrocatalysis owing to their flexible element compositions and crystal structures,which can evidently reduce the noble-metal content and meanwhile significantly promote electrocatalytic performance.In this review,the current research progress in low-Ir/Ru perovskite oxides for acidic OER electrocatalysis is comprehensively summarized.Initially,we present a brief introduction to general issues relevant to acidic OER catalyzed by low-Ir/Ru perovskite oxides,such as the actual active species,OER mechanisms,inverse activity-stability relationship,and performance evaluation metrics.Subsequently,we present a thorough overview of various low-Ir/Ru perovskite oxides for acidic OER electrocatalysis,including single perovskites,double perovskites,triple perovskites,quadruple perovskites,Ruddlesden-Popper perovskites,and other complex perovskite-derived oxides,with emphasis on the intrinsic factors contributing to their exceptional performance and structure-property-performance correlation.Finally,remaining challenges and some promising insights to inspire future studies in this exciting field are provided.
基金financially supported by Yunnan Major Scientific and Technological Projects(No.202202AG050017-02)Yunnan Fundamental Research Projects(No.202101BE070001-017)the National Natural Science Foundation of China(Nos.52101258 and 52272202)
文摘The sluggish kinetics of the oxygen evolution reaction(OER)process impedes the exploration of green hydrogen via water splitting.Herein,we design and synthesize vanadium-doped CoSn(OH)_(6)perovskite hydroxide catalysts by Fe^(3+)etching during the hydrothermal and chemical deposition process.The as-prepared CoVSn(OH)_(6)@CoVSnFe(OH)_(x)-4 catalyst exhibits a lowoverpotential of 225 mV at 10 mA·cm^(-2)with a Tafel slope of 30.47 mV·dec^(-1).An overall water splitting electrolyzer(CoVSn(OH)_(6)@CoVSnFe(OH)_(x)-4‖Pt/C)is constructed,delivering a voltage of 1.48 V at a current density of10 mA·cm^(-2)with excellent durability.The dynamic phase evolution during the OER process is revealed by in situ Raman and XPS measurement,which represents that the introduced V and Fe ions facilitate the formation of active CoOOH as well as modify the electronic structure of the catalyst.Density functional theory(DFT)calculations further evidence that V and Fe introduction optimize the adsorption energies of oxygen intermediates*OH and*O,respectively,thereby enabling a synergistic optimization of the multi-step OER process and advancing electrocatalytic performance.
基金supported by the National Natural Science Foundation of China(Grant Nos.21433003,21805064 and 21773049)National Key Research and Development Program of China(Program No.2016YFB0101207)。
文摘ABO_(3)-type perovskite oxides(e.g.,LaCoO_(3))with flexible and adjustable A-and B-sites are ideal model catalysts to unravel the relationship between the electronic structure and electrocatalytic activity(e.g.,oxygen reduction/evolution reactions,ORR/OER).It has been well understood in our recent work that the secondary metal dopant at B-site(e.g.,Mn in LaMn_(x)Co_(1-x)O_(3))can regulate the electronic structure and improve the ORR/OER activity.In this work,the Mn-Ni pairs are employed as the dual dopant in LaMn_(x)Ni_(y)Co_(z)O_(3)(x+y+z=1)catalysts toward bifunctional ORR and OER.The structure-property relationships between the triple metal B-site(Mn,Ni and Co)and the electrochemical performance are particularly investigated.Compared to the individual Mn doping(e.g.,LaMnCoO3(Mn:Co=1:3)catalyst),the dual Mn-Ni doping significantly improves the ORR mass activity@0.8 V by 1.54 times;meanwhile,the OER overpotential@10 mA cm^(-2) is reduced from 420 to 370 mV,and the OER current density at 1.55 V is increased by 2.43 times.Reasonably,the potential gap between EDRR@-1 mA cm^(-2) and EDER@10 mA cm^(-2) is achieved as only 0.76 V by using the optimal LaMn_(x)Ni_(y)Co_(z)O_(3)(x:y:z=1:2:3)catalyst.It is revealed that the dual Mn-Ni dopant efficiently optimizes electron structures of the LaMnNiCoO_(3)(1:2:3)catalyst,which not only decreases the e_(g) orbital electron number,but also modulates the O 2 p-band closer to the Femi level,accounting for the enhanced bifunctional activity.
基金financially supported by the Key Research and Development Program of Hainan Province(No.ZDYF2022GXJS006)the National Natural Science Foundation of China(Nos.52231008,52201009 and 52001227)+2 种基金Hainan Provincial Natural Science Foundation of China(No.223RC401)the Education Department of Hainan Province(No.Hnky2023ZD-2)the Starting Research Funds of the Hainan University of China(Nos.KYQD(ZR)-21105 and XJ2300002951)。
文摘Oxygen evolution reaction(OER)is a kinetically harsh four-electron anode reaction that requires a large overpotential to provide current and is of great importance in renewable electrochemical technique.Ir/Rubased perovskite oxides hold great significance for application as OER electrocatalysts,due to that their multimetal-oxide forms can reduce the use of noble metals,and their compositional tunability can modulate the electronic structure and optimize OER performance.However,high operating potentials and corrosive environments pose a serious challenge to the development of durable Ir-based and Ru-based perovskite electrocatalysts.Tremendous efforts have been dedicated to improving the Ir/Ru-based perovskite activity to enhance the efficiency;however,progress in improving the durability of Ir/Ru-based perovskite electrocatalysts has been rather limited.In this review,the recent research progress of Ir/Ru-based perovskites is reviewed from the perspective of heteroatom doping,structural modulation,and formation of heterostructures.The dissolution mechanism studies of Ir/Ru and experimental attempts to improve the durability of Ir/Ru-based perovskite electrocatalysts are discussed.Challenges and outlooks for further developing Ru-and Irbased perovskite oxygen electrocatalysts are also presented.
基金the financial supports from the National Natural Science Foundation of China:Grant No.21922507 and 21771079Fok Ying Tung Education Foundation:Grant No.161011+3 种基金Jilin Province Science and Technology Development Plan 20170101141JCProgram for JLU Science and Technology Innovative Research TeamNational Natural Science Foundation of China (No.21621001)111 Project (No.B17020) for financial support。
文摘Development of cost-effective and highly active oxygen evolution catalysts operating well in acidic media is a critical challenge in proton exchange membrane water electrolysis.Herein,we present a class of iridium-based 12L-perovskites(Ba4MIr3O12;M=Pr,Bi,Nb)as novel low-iridium electrocatalysts for oxygen evolution reaction under acidic conditions.These 12L-perovskites contain trinuclear face-shared Ir O6octahedral strings—unique subunits that are not found in the previously-reported iridium-based electrocatalysts.The catalytic activities of 12L-perovskites(Ba4MIr3O12)are found to be related to the location of O 2p-band center,which is influenced by the B-site nonprecious element(i.e.,Pr,Bi or Nb).Our experimental results show that Ba4PrIr3O12is the most active electrocatalyst among the materials we synthesize,and contains 55%less iridium than the benchmark catalyst IrO2,while exhibiting higher catalytic activity.In the presence of Ba4PrIr3O12,transient leaching process of Ba and Pr takes place during electrochemical process,contributing to the surface reconstruction of the pristine catalysts.Further experimental results reveal that the formation of under-coordinated Ir Ox-rich surface and easier generation of active intermediate IrVare mainly responsible for the good activity of Ba4PrIr3O12.
基金supported by the “Transformational Technologies for clean Energy and Demonstration”,Strategic Priority Research Program of the Chinese Academy of Sciences(XDA2100000)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2014237)+1 种基金the National Natural Science Foundation of China(21876183)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(YJKYYQ20180066)~~
文摘Effective electrocatalysis is crucial for enhancing the efficiency of water splitting to obtain clean fuels.Herein,we report a system of interesting and high-performance Sr-doped perovskite electrocatalysts with porous structures,obtained via a facile molten salt method and applied in the oxygen evolution reaction(OER).With increasing the Sr content,the valence states of Co and Fe ions do not clearly increase,according to the Co-L2,3 and Fe-L2,3 as well as the Co-K and the Fe-K X-ray absorption spectroscopy,whereas doped holes are clearly observed in the 0-K edge.High-resolution transmission electron microscopy indicates the appearance of an amorphous layer after the electrochemical reaction.We conclude that the formation of the amorphous layer at the surface,induced by Sr doping,is crucial for achieving high OER activity,and we offer insights into the self-reconstruction of the OER catalyst.
文摘The development of efficient oxygen evolution electrocatalysts with reduced noble metal uses is a critical challenge for the deployment of various advanced energy conversion technologies.Here,a series of lanthanide-contained 6H-perovskites with a formula of Ba3LnIr2〇9(Ln=lanthanides)are investigated as oxygen evolution electrocatalysts,whose active subunits(i.e.,face-sharing Ir〇6 dimers)can be regulated by the lanthanides in terms of catalytic activity.By using density functional theory(DFT)calculations,we establish the theoretical trend in activity for Ba3LnIr2〇96H-perovskites,the activity of which is correlated with the difference of adsorption free energy(△G〇-△Goh)between O*and OH*reaction intermediates.We further establish a volcano curve between△Go—△Goh and the calculated 0 p-band center Among the Ba3LnIr2〇96H-perovskites,Ba3Lalr2〇9 locates at the peak of volcano curve,and correspondingly is the most active electrocatalyst due to the optimal 0 p-band property.
基金financial supports from the Youth Innovation Fund of Dalian Institute of Chemical Physics (DICP I202126)the Strategic Priority Research Program of Chinese Academy of Sciences (XDB17020400)。
文摘The oxygen evolution reaction (OER) dominates the efficiency of electrocatalytic water splitting owing to its sluggish kinetics.Perovskite oxides (ABO_(3)) have emerged as promising candidates to accelerate the OER process owing to their high intrinsic activities and tailorable properties.Fe ions in perovskite oxides have been proved to be a highly catalytic element for OER,while some Fe-based perovskites such as SrTi_(0.8)Fe_(0.2)O_(3-δ)(STF) and La_(0.66)Ti_(0.8)Fe_(0.2)O_(3-δ)(LTF) exhibit inferior OER activity.Yet the essential reason is still unclear and the effective method to promote the activity of such perovskite is also lacking.Herein,an in-situ exsolution strategy was proposed to boost the OER by migrating Fe from the bulk to the surface.Significantly enhanced OER activity was achieved on STF and LTF perovskites with surfacedecorated oxygen vacancies and Fe nanoparticles.In addition,theoretical calculation confirmed that the oxygen vacancies and Fe nanoparticle on surface could lower the overpotential of OER by facilitating the adsorption of OH^(-).From this study,migration of the active elements in perovskite is found to be an effective strategy to increase the quantity and activity of active sites,providing new insights and understanding for designing efficient OER catalysts.
基金financially supported by the Australian Research Council (Discovery Early Career Researcher Award No. DE190100005)the support of the Australian Research Council (Grant No. FT160100207)the ontinued support from the Queensland University of Technology (QUT) through the centre for Materials Science。
文摘The oxygen evolution reaction(OER) plays a crucial role in many electrochemical energy technologies,and creating multiple beneficial factors for OER catalysis is desirable for achieving high catalytic efficiency.Here,we highlight a new halogen-chlorine(Cl)-anion doping strategy to boost the OER activity of perovskite oxides.As a proof-of-concept,proper Cl doping at the oxygen site of LaFeO3(LFO) perovskite can induce multiple favorable characteristics for catalyzing the OER,including rich oxygen vacancies,increased electrical conductivity and enhanced Fe-O covalency.Benefiting from these factors,the LaFeO2.9-δCl0.1(LFOCl) perovskite displays significant intrinsic activity enhancement by a factor of around three relative to its parent LFO.This work uncovers the effect of Cl-anion doping in perovskites on promoting OER performance and paves a new way to design highly efficient electrocatalysts.
基金funding support by the National Natural Science Foundation of China (Grant No. 21872116)financial support by the National Natural Science Foundation of China (Grant No. 21621091 and 21373166)+5 种基金funding supported by the EU (ERC CoG HyMAP 648319)Spanish AEI (NyMPhA PID2019-106315RB-I00)“Comunidad de Madrid” and European Structural Funds for their financial support to FotoArt-CM project (S2018/NMT-4367)the Fundación Ramón Arecesfinancial support by the China Scholarship Council (CSC)the Sino-German Mobility Program (Grant No. M-0377)。
文摘Perovskite LaCoO_(3) is being increasingly explored as an effective low-cost electrocatalyst for the oxygen evolution reaction(OER).Sr doping in LaCoO_(3)(La1-xSrxCoO_(3))has been found to substantially increase its catalytic activity.In this work,we report a detailed study on the evolution of the electronic structure of La1-xSrxCoO_(3) with 0≤x≤1 and its correlation with electrocatalytic activity for the OER.A combination of X-ray photoemission spectroscopy(XPS)and X-ray absorption spectroscopy(XAS)was used to unravel the electronic density of states(DOS)near the Fermi level(EF),which provide insights into the key electronic structure features for the enhanced OER catalytic activity.Detailed analysis on the Co L-edge XAS suggest that LaCoO_(3) has a low spin state with t_(2g)^(6) e_(g)^(0) configuration at room temperature.This implies that the high OER catalytic activity of LaCoO_(3) should not be rationalized by the occupancy of eg=1 descriptor.Substituting Sr^(2+) for La^(3+) in LaCoO_(3) induces Co4+oxidation states and effectively dopes hole states into the top of valence band.A semiconductor-to-metal transition is observed for x>0.2,due to the holeinduced electronic DOS at the EF and increased hybridization between Co 3 d and O 2 p.Such an electronic modulation enhances the surface adsorption of the*OH intermediate and reduces the energy barrier for interfacial charge transfer,thus improving the OER catalytic activity in La_(1-x)Sr_(x)CoO_(3).In addition,we found that the La_(1-x)Sr_(x)CoO_(3) surface undergoes amorphization after certain period of OER measurement,leading to a partial deactivation of the electrocatalyst.High Sr doping levels accelerated the amorphization process.
基金financial support from the National Natural Science Foundation of China (52203070)the Open Fund of State Key Laboratory of New Textile Materials and Advanced Processing Technologies (FZ2022005)+2 种基金the Open Fund of Hubei Key Laboratory of Biomass Fiber and Ecological Dyeing and Finishing (STRZ202203)the financial support provided by the China Scholarship Council (CSC)Visiting Scholar Programfinancial support from Institute for Sustainability,Energy and Resources,The University of Adelaide,Future Making Fellowship,Australia。
文摘The incorporation of partial A-site substitution in perovskite oxides represents a promising strategy for precisely controlling the electronic configuration and enhancing its intrinsic catalytic activity.Conventional methods for A-site substitution typically involve prolonged high-temperature processes.While these processes promote the development of unique nanostructures with highly exposed active sites,they often result in the uncontrolled configuration of introduced elements.Herein,we present a novel approach for synthesizing two-dimensional(2D)porous GdFeO_(3) perovskite with A-site strontium(Sr)substitution utilizing microwave shock method.This technique enables precise control of the Sr content and simultaneous construction of 2D porous structures in one step,capitalizing on the advantages of rapid heating and cooling(temperature~1100 K,rate~70 K s^(-1)).The active sites of this oxygen-rich defect structure can be clearly revealed through the simulation of the electronic configuration and the comprehensive analysis of the crystal structure.For electrocatalytic oxygen evolution reaction application,the synthesized 2D porous Gd_(0.8)Sr_(0.2)FeO_(3) electrocatalyst exhibits an exceptional overpotential of 294 mV at a current density of 10 mA cm^(-2)and a small Tafel slope of 55.85 mV dec^(-1)in alkaline electrolytes.This study offers a fresh perspective on designing crystal configurations and the construction of nanostructures in perovskite.
基金supported by the National Natural Science Foundation of China(No.22108043)Natural Science Foundation of Guangdong Province,China(No.2023A1515012711).
文摘Cobalt-rich perovskite oxides play a paramount role in catalyzing oxygen evolution reaction(OER)on account of their acceptable intrinsic activity but are still challenging due to the high costs and undesired stability.In response to the defects,herein,the Mg-incorporated perovskite cobaltite SrCo_(0.6)Fe_(0.3M)g_(0.1)O_(3-δ)(SCFM-0.1)is proposed as a novel earth-abundant and durable OER electrocatalyst.A well-consolidated cubic-symmetry structure and more active oxygen intermediates are enabled upon Mg substitution.Hence,the optimized SCFM-0.1 perovskite oxide achieves prominent OER electrocatalytic performance,that is,a low overpotential of only 320 mV at 10 mA cm^(-2),a small Tafel slope of 65 mV dec^(-1),as well as an outstanding durability within 20 h,substantially outperforming that of the pristine SrCo_(0.7)Fe_(0.3)O_(3-δ)and benchmark Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)and IrO_(2) catalysts.The strong pHdependent behavior associated with lattice oxygen activation mechanism for SCFM-0.1 catalyst is also confirmed.This work paves a unique avenue to develop cost-effective and robust perovskite cobaltites for efficient OER electrocatalysis.
基金the National Natural Science Foundation of China(No.41807213)the Hydrogeo-logical Survey Project of Huangshui River(No.DD20190331).
文摘Water splitting is important to the conversion and storage of renewable energy,but slow kinetics of the oxygen evolution reaction(OER)greatly limits its utility.Here,under visible light illumination,the p-n WO_(3)/SnSe_(2)(WS)heterojunction significantly activates OER catalysis of CoFe-layered double hydroxide(CF)/carbon nanotubes(CNTs).Specifically,the catalyst achieves an overpotential of 224 mV at 10 mA cm^(-2)and a small Tafel slope of 47 mV dec^(-1),superior to RuO_(2)and most previously reported transition metal-based OER catalysts.The p-n WS heterojunction shows strong light absorption to produce photogenerated carriers.The photogenerated holes are trapped by CF to suppresses the charge recombination and facilitate charge transfer,which accelerates OER kinetics and boost the activity for the OER.This work highlights the possibility of using heterojunctions to activate OER catalysis and advances the design of energy-efficient catalysts for water oxidation systems using solar energy.
基金supported by Australian Research Council Discovery Projects(DP230101625 and DP200103568)Australian Research Council Future Fel owships(FT180100387 and FT160100281)QUT ECR Scheme Grant(no.2020001179)
文摘Metal exsolution engineering has been regarded as a promising strategy for activating intrinsically inert perovskite oxide catalysts toward efficient oxygen evolution reaction.Traditional metal exsolution processes on perovskites are often achieved by using the reducing hydrogen gas;however,this is not effective for the relatively stable phase,such as Ruddlesden-Popper perovskite oxides.To address this issue,triphenylphosphine is proposed to be a reduction promotor for accelerating the reduction and migration of the target metal atoms,aiming to achieve the effective exsolution of metallic species from Ruddlesden-Popper-type parent perovskites.Upon oxygen evolution reaction,these exsolved metallic aggregates are reconstructed into oxyhydroxides as the real active centers.After further modification by lowpercentage iridium oxide nanoclusters,the optimal catalyst delivered an overpotential as low as 305 mV for generating the density of 10 mA cm^(-2),outperforming these reported noble metal-containing perovskite-based alkaline oxygen evolution reaction electrocatalysts.This work provides a potential approach to activate catalytically inert oxides through promoting surface metal exsolution and explores a novel class of Ruddlesden-Poppertype oxides for electrocatalytic applications.
文摘We report a facile way to prepare sulfur(S) doped Ni4/5 Fe1/5-layered double hydroxide(LDH) electrocatalysts for oxygen evolution reaction(OER). The influence of S doping amount on the OER activity of the resulted Ni Fe-LDHs was studied and the optimal surface S content was ca. 0.43 at%. The developed S-doped Ni Fe-LDH exhibits excellent OER catalyst activity in 1.0 M KOH with overpotential of only 257 m V at the current density of 10 m A cm^-2. Moreover, the catalyst could maintain high activity after 30 h stability test. The high activity of the S-doped Ni Fe-LDH catalysts may originate from the synergistic effect between S and the Fe sites. This work provides a simple but efficient way to improve the OER performance of transition metal oxides/(oxy)hydroxides.
基金supported by the National Natural Science Foundation of China(No.22179032,51871088,51771068,52171176)the Natural Science Foundation of Hebei Province(No.B2021202011)。
文摘The primary challenge in rechargeable Zn-air batteries lies in developing a catalyst capable of simultaneously improving performance for oxygen reduction reaction(ORR)during discharge and oxygen evolution reaction(OER)during charge.Engineering spin configuration is essential for enhancing the intrinsic bifunctional activity and stability of spinel Co_(3)O_(4).Herein,Cr^(3+)is doped into Co_(3)O_(4),inducing directional distortion of CoO_6 octahedron to modify crystal field splitting energy,pushing Co_(Oh)toward intermediate-spin(IS)configuration(t_(2g)^(5)e_(g^(1)))with optimized eg occupancy of 1.04.As a result,9%Cr-Co_(3)O_(4)demonstrates an excellent bifunctional activity and remarkable rechargeable Zn-air battery performance that even outperforms Pt/C+RuO_(2).Density functional theory(DFT)studies reveal that IS Co_(Oh)not only regulates the adsorption energy of ORR/OER species but also transform the O_(2)adsorption configuration from end-on to Griffith configuration,thus modifies the mechanisms of both ORR and OER process and optimize bifunctional activity and selectivity.This work provides mechanistic insight into the spin origin of ORR/OER catalysis and highlights a promising strategy for developing robust bifunctional electrocatalysts.
基金support of the National Natural Science Foundation of China(22275035).
文摘Transition metal phosphides exhibit excellent efficiency in the oxygen evolution reaction under alkaline conditions,and they have garnered widespread recognition.Currently,most studies have focused on the evolution and role of metal cations in the oxygen evolution reaction process,while attention to phosphorus elements is relatively scarce.Actually,phosphides possess unique properties that distinguish them from other metal compounds,and the role of phosphorus in them cannot be ignored.This study used nickel phosphide(Ni_(2)P)as a model catalyst to reveal the reconstruction and dynamic behavior of anions under alkaline conditions through cyclic voltammetry.The results indicate that as the cycle progresses,surface phosphides are converted into active oxyhydroxides.It is worth noting that the presence of the P element accelerates the rapid completion of the reconstruction process but also exhibits triple synergistic functions.First,the internal phosphorus nuclei of the active layer act as conductive scaffolds,effectively enhancing the efficiency of electron conduction.Second,the oxygen-containing anions formed in situ on metal hydroxides optimize the adsorption of reaction intermediates.Finally,the phosphorus atoms dissolved in the electrolyte suppress nickel loss,improve stability,and increase the electrochemical activity specific surface area,exposing more active sites.This study elucidates the oxygen evolution reaction mechanism of phosphides from a novel perspective,enhancing comprehension of surface reconstruction phenomena and the characteristics of active sites,guiding the rational design of phosphide pre-catalysts.
基金supported by the Major Science and Technology Special Plan of Yunnan Province(Nos.202302AB080012 and 202402AB080004)the National Natural Science Foundation of China(No.22264025)+1 种基金the Basic Research Foundation of Yunnan Province(Nos.202401AS070033 and 202501AT070055)the Reserve talents for young and middleaged academic and technical leaders project of Yunnan Province(No.202405AC350071).
文摘Oxygen evolution reaction(OER)is a key step in hydrogen production by water electrolysis technology.How-ever,developing efficient,stable,and low-cost OER electrocatalysts is still challenging.This article presents the preparation of a series of novel copper iridium nanocatalysts with heterostructures and low iridium content for OER.The electrochemical tests revealed higher OER of Cu@Ir_(0.3) catalyst under acidic conditions with a generated current density of 10 mA/cm^(2) at only 284 mV overpotential.The corresponding OER mass activity was estimated to be 1.057 A/mgIr,a value 8.39-fold higher than that of the commercial IrO_(2).After 50 h of endurance testing,the Cu@Ir_(0.3) catalyst preserved excellent catalytic activity with a negligible rise in overpotential and maintained a good heterostructures.Cu@Ir_(0.3) The excellent OER activity can be attributed to its heterostructure,as con-firmed by density functional theory(DFT)calculations,indicating that Cu@Ir The coupling between isoquanta causes charge redistribution,optimizing the adsorption energy of unsaturated Ir sites for oxygen intermediates and reducing the energy barrier of OER free energy determining the rate step.In summary,this method provides a new approach for designing efficient,stable,and low iridium content OER catalysts.
基金financial support from Universidad de Santiago de Chile through the Dirección de Investigación Científica y Tecnológica(DICYT,Project No.022442PC)the Vicerrectoría de Investigación,Innovación y Creación,Fondo de Equipamiento Científico y Tecnológico(FONDEQUIP,EQM180195)+6 种基金FONDECYT Postdoctoral project(No.3260881)support from the Agencia Nacional de Investigación y Desarrollo(ANID,Chile)through the FONDECYT Postdoctoral Project No.3250677the Subvención a la Instalación en la Academia(SIA No.85250233)support from RPM's laboratory at Universidad Técnica Federico Santa María(UTFSM)support from the UK Engineering and Physical Sciences Research Council through the Li ME project(EP/N007638/1)support from ANID through the FONDECYT Iniciación Project No.11230550the Fondo de Financiamiento de Centros de Investigación enÁreas Prioritarias(FONDAP,No.1523A0006,Solar Energy Research Center—SERC-Chile,second extension).
文摘Self-supported,hot-pressed FeNiCoCuMo high-entropy alloy(HEA)electrodes were fabricated and characterized by X-ray diffraction(XRD),high-resolution transmission electron microscopy(HR-TEM),and energy dispersive spectroscopy(EDS),confirming a face-centered cubic(FCC)matrix with minor body-centered cubic(BCC)phase(~1wt%).We map the redox behavior of the individual constituents(Fe,Ni,Co,Cu,and Mo)and compare it with HEA to reveal solid-solution synergy(“cocktail effect”).Electrochemistry(cyclic voltammetry(CV)/linear sweep voltammetry(LSV)/Tafel in 1.0 M KOH)and X-ray photoelectron spectroscopy(XPS)show broadened redox features for HEA and Ni/Co-rich(oxy)hydroxide signatures with MoOx contributions.Triplicate electrodes(M1–M3)deliver an average overpotential of 370 m V at 10mA·cm^(-2)and a Tafel slope of 78 mV·dec^(-1),outperforming monometallic references and remaining competitive with the literature-reported RuO_(2).Chronopotentiometry 100 h evidence stable operation;post-mortem XRD indicates a thin reconstructed surface while the bulk remains FCC-dominated.Density functional theory(DFT)supports broadened electronic states near the Fermi level and enhanced charge transfer.Overall,structure and computation link compositional disorder,surface reconstruction,and oxygen evolution reaction(OER)kinetics in a robust anode for alkaline oxygen evolution.
基金the support from the National Natural Science Foundation of China(21773146,22171176 and 22102092)the Fok Ying-Tong Education Foundation for Outstanding Young Teachers in University+2 种基金the Research Funds of Shaanxi Normal Universitythe Fundamental Research Funds for the Central Universitiesthe NRF of Korea(NRF-2021R1A3B1076539 and NRF-2020R1I1A1A01074630)。
文摘Electrocatalytic oxygen reduction and evolution reactions are involved in new energy conversion and storage technologies,such as various fuel cells and metal-air batteries and also water splitting devices[1,2].However,both reactions are very slow in kinetics,and thus catalysts are required[3,4].
