Polycrystalline perovskite oxide particles are promising candidates for cathode materials in solid oxide fuel cells.However,their limited activity and stability pose significant challenges for practical applications.I...Polycrystalline perovskite oxide particles are promising candidates for cathode materials in solid oxide fuel cells.However,their limited activity and stability pose significant challenges for practical applications.In this study,we demonstrate a novel approach to achieve both high activity and durability in a PrBaCo_(2)O_(5+δ) catalyst through a simple epitaxial layer growth strategy.We found that an amorphous precursor of the highly durable catalyst SmBa_(0.5)Ca_(0.5)CoCuO_(5+δ) can spontaneously adhere to the surface of PrBaCo_(2)O_(5+δ) particles.Upon heat treatment,it grows along the perovskite lattice,forming a heteroepitaxial layer with just a few atomic layers thickness.This heterostructure enhances the operational stability of PrBaCo_(2)O_(5+δ) transforming a 78% decrease over 100 h into a 7% increase.After 100 h,the power output density of the cell with the modified sample is more than 500% higher than that of unmodified PrBaCo_(2)O_(5+δ.)This work presents a new strategy for fabricating heteroepitaxial layers on polycrystalline ceramic catalysts and introduces a pioneering approach for developing high-performance oxygen reduction catalysts and related materials.展开更多
Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electroc...Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electrocatalysts with high SSA and optimized structure is of great significance but remains a tremendous challenge.Herein,we propose a general strategy for fabrication of mesoporous perovskite oxide nanosheets(MPONs)with controllable atomic doping via self-sacrificial template-induced nanostructure modulation.A variety of MPONs including LaFeO_(3),A-site-doped LaFeO_(3)(A-LaFeO_(3),where A is Pr,Nd,Sm,Eu,or Gd)and B-site-doped LaFeO_(3)(B-LaFeO_(3),where B is Mn,Co,Ni,Cu,or Zn)have been achieved.Interestingly,it is discovered that the catalytic activities of A-LaFeO_(3) MPONs as OER catalysts are overall higher than those of B-LaFeO_(3) ones.Especially,the screened Eu-LaFeO_(3) MPONs only require a low overpotential of 267 mV at 10 mA cm^(−2),outperforming most reported perovskite oxides.The superior catalytic activity of Eu-LaFeO_(3) MPONs is attributed to their favorable porous structure,which increases the density of active sites,and enhanced lattice oxygen participation,which improves the intrinsic activity.This study provides guidance for the design and controlled synthesis of advanced rare-earth-doped MPONs with ultrahigh SSA for enhanced electrocatalysis.展开更多
The electrochemical nitrogen reduction reaction(NRR)under ambient conditions presents a promising approach for the eco-friendly and sustainable synthesis of ammonia,with a continuous emergence of potential electrocata...The electrochemical nitrogen reduction reaction(NRR)under ambient conditions presents a promising approach for the eco-friendly and sustainable synthesis of ammonia,with a continuous emergence of potential electrocatalysts.However,the low solubility and limited diffusion of N_(2)significantly hinder the achievement of satisfactory performance.In this context,we report an effective strategy to enhance NRR activity by introducing a metal-organic framework(MOF)membrane,specifically MIL-53(Al),onto a perovskite oxide(LiNbO_(3)),denoted as LN@MIL-X(X=0.2,0.4 and 0.6).The MIL-53(Al)membrane selectively recognizes and concentrates N_(2)at the catalyst interface while simultaneously repelling water molecules,thereby inhibiting the hydrogen evolution reaction(HER).This ultrathin nanostructure significantly improves the NRR performance of LN@MIL-X compared to pristine LiNbO_(3).Notably,LN@MIL-0.4 exhibits a maximum NH_(3)yield of 45.25 mg h^(-1)mg_(cat.)^(-1)with an impressive Faradaic efficiency(FE)of 86.41%at-0.45 V versus RHE in 0.1 mol L^(-1)Na_(2)SO_(4).This work provides a universal strategy for the design and synthesis of perovskite oxide electrocatalysts,facilitating high-efficiency ammonia synthesis.展开更多
Proton ceramic fuel cell efficiently converts chemical energy into electrical energy,representing a pivotal component of future energy systems.However,its current performance is hindered by limitations in cathode and ...Proton ceramic fuel cell efficiently converts chemical energy into electrical energy,representing a pivotal component of future energy systems.However,its current performance is hindered by limitations in cathode and electrolyte materials,thereby impeding commercialization.Anion doping emerges as a promising strategy to enhance the electrochemical efficiency of perovskite-based cathodes and electrolytes.However,integrating this approach within a single-cell structure still requires further research.In this study,F-doped perovskite oxides BaCo_(0.4)Fe_(0.4)Zr_(0.1)Y_(0.1)O_(2.9-δ)F_(0.1)(BCFZYF)and BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(2.9-δ)F_(0.1)(BZCYYbF)were synthesized for use as the cathode and electrolyte,respectively,in proton ceramic fuel cells.Our findings demonstrate that F-doped perovskite oxides exhibit superior electrochemical performance and enhanced structural stability.Furthermore,doping both electrodes and electrolytes with F ions improves their interfacial compatibility.The cell configuration BCFZYF|BZCYYbF|Ni-BZCYYbF achieved a peak power density of 998 mW·cm^(−2)at 650℃using H_(2)as fuel,and it maintained stable operation for over 400 h at 550℃with a current density of 400 mA·cm^(−2).This research underscores an effective strategy for enhancing the performance and durability of proton ceramic fuel cells.展开更多
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 disordered macroporous-mesoporous La_(1-x)Ce_(x)CoO_(3)catalysts were prepared by complexcombustion method with ethylene glycol as complexing agent at relatively low calcination temperature.The samples were charac...The disordered macroporous-mesoporous La_(1-x)Ce_(x)CoO_(3)catalysts were prepared by complexcombustion method with ethylene glycol as complexing agent at relatively low calcination temperature.The samples were characterized by means of X-ray diffraction,N_(2)adsorption-ndash;desorption,Xray photoelectron spectroscopy,transmission electron microscopy,hydrogen temperature-programmed reduction and soot temperature-programmed reduction,and so on.The results show that the use of complexing agent and relatively low calcination temperature increase the specific surface area of the catalyst and have abundant pore structure.The Ce ions introduced into lattice of LaCoO_(3)mainly exist in the form of tetravalent.At the same time,Ce ions enhance the redox performance of the catalyst and the mobility of active oxygen species,which enhances the catalytic activity of the catalyst for soot combustion.The results of activity test show that La0.9Ce0.1CoO3 catalyst exhibits the highest activity in the absence of NO and NO2,and its T10,T50 and T90 are 371,444,and 497℃,respectively.At the same time,a possible reaction mechanism is proposed in this study based on the turnover frequency(TOF)calculated by isothermal anaerobic titrations,XPS and XRD results.展开更多
In this paper, the partial oxidation of methane to synthesis gas using lattice oxygen of La1- SrxMO3-λ (M=Fe, x ...In this paper, the partial oxidation of methane to synthesis gas using lattice oxygen of La1- SrxMO3-λ (M=Fe, x Mn) perovskite oxides instead of molecular oxygen was investigated. The redox circulation between 11% O2/Ar flow and 11% CH4/He flow at 900℃ shows that methane can be oxidized to CO and H2 with a selectivity of over 90.7% using the lattice oxygen of La1- SrxFeO3-λ (x≤0.2) perovskite oxides in an appropriate reaction condition, while the lost lattice x oxygen can be supplemented by air re-oxidation. It is viable for the lattice oxygen of La1- SrxFeO3-λ (x≤0.2) perovskite x oxides instead of molecular oxygen to react with methane to synthesis gas in the redox mode.展开更多
Magnesia modified LaCoO3 was prepared by a facile one-step sol-gel method and used for removal of dilute methane.Compared with the conventional doping technique,the obtained LaCoO3@MgO-x exhibits pseudo core-shell str...Magnesia modified LaCoO3 was prepared by a facile one-step sol-gel method and used for removal of dilute methane.Compared with the conventional doping technique,the obtained LaCoO3@MgO-x exhibits pseudo core-shell structure and shows superior catalytic activity.The methane conversion exceeds90%at 532℃on LaCoO3@MgO-0.1,while only 60%of methane is conversed using the doped perovskite LaCo0.9Mg0.1O3.The high catalytic performance of LaCoO3@MgO-0.1 is mainly attributed to the adjustment of surface acid-base properties by the MgO shell structure.According to density functional theory(DFT)calculation,the methane is more likely to be adsorbed and cracked on LaCoO3@MgO-0.1.The in situ DRIFTS shows that CH3-O-CH3 intermediate specie is formed.The pseudo core-shell structure also enhances the stability and the LaCoO3@MgO-0.1 maintains high activity after working for 100 h.The above results demonstrate that surface modification by magnesia is an effective strategy for improving LaCoO3 catalytic performance.展开更多
A series of BaCe0_(3)modified with different rare earth elements(La,Y,Pr)were synthesized by coprecipitation and calcination and the effect of rare earth elements for catalytic ammonia synthesis under mild conditions ...A series of BaCe0_(3)modified with different rare earth elements(La,Y,Pr)were synthesized by coprecipitation and calcination and the effect of rare earth elements for catalytic ammonia synthesis under mild conditions was studied.The ammonia synthesis performance tests show that 2.5%Ru/BaCe_(0.9)La_(0.1)O_(3-δ)catalyst(All the percentages of Ru in this article are in mass fraction)exhibits the highest ammonia synthesis rate(34 mmol/(g·h))at 3 MPa,450℃,and no sign of deactivation after 100 h of reaction.H_(2)-TPR and XPS analyses indicate that the introduction of La increases the amount of oxygen vacancies of the catalyst,which is beneficial to increasing the electron density of Ru surface.HRTEM analysis shows that the Ru particle size is reduced greatly after La is introduced,which facilitates the catalyst generating more Bs-type sites(active sites of Ru species for N=N dissociation).CO_(2)-TPD analysis indicates that BaCe_(0.9)La_(0.1)O_(3-δ)has stronger basicity,which promotes electrons transfer from support to Ru.This work provides an effective method for design and synthesis of Ru-based multi-element composite perovskite oxide catalysts.展开更多
Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9CO0.1O3 perovskite oxides as oxygen carrier for partial oxidation of methane in the absence of gaseous oxygen was investigated by continuous flow reaction and s...Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9CO0.1O3 perovskite oxides as oxygen carrier for partial oxidation of methane in the absence of gaseous oxygen was investigated by continuous flow reaction and sequential redox reaction, Methane was oxidized to syngas with high selectivity by oxygen species of perovskite oxides in the absence of gaseous oxygen. The sequential redox reaction revealed that the structural stability and continuous oxygen supply in redox reaction decreased over La0.8Sr0.2Fe0.9Co0. 1O3 oxide, while LaFeO3 and La0.8Sr0.2FeO3 exhibited excellent structural stability and continuous oxygen supply.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
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
Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite ox...Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite oxides,(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2) with n=5,8,and 12(LSTNn) for application as catalysts of CO_(2) electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method.It is found that the density,size,and distribution of exsolved Ni nanoparticles are determined by the number of n in LSTNn due to the different stack structures of TiO_6 octahedra along the c axis.The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies,and the Ni metallic nanoparticles afford much more active sites.The results show that LSTNn cathodes can successfully be manipulated the activity by controlling both the n number and Ni exsolution.Among these LSTNn(n=5,8,and 12),LSTN8 renders a higher activity for electrolysis of CO_(2) with a current density of 1.50A cm^(-2)@2.0 V at 800℃ It is clear from these results that the number of n in(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2)with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC.展开更多
The urgent need for decarbonized hydrogen production to achieve carbon‐neutral targets has highlighted the critical role of water electrolysis technology in advancing sustainability in various fields.However,the gap ...The urgent need for decarbonized hydrogen production to achieve carbon‐neutral targets has highlighted the critical role of water electrolysis technology in advancing sustainability in various fields.However,the gap in economic efficiency between green hydrogen,generated by renewable electricity‐driven water electrolysis,and gray hydrogen,generated by the consumption of fossil fuels,remains a challenge.Therefore,the exploration of cost‐effective,active,and stable electrocatalysts toward water‐splitting reactions is essential.Owing to their high‐tolerance crystal structures,flexible elemental compositions,and adjustable electronic properties,perovskite oxides provide a vast material library for customizing next‐generation electrocatalysts.Additionally,perovskite oxides are increasingly being developed into ideal model catalysts for unraveling scientific laws and theories,emphasizing the significance of investigating their important characteristics(e.g.,structure‐performance relationship,electronic property regulation,catalytic mechanism,and dynamic structural evolution).This review summarizes recent advances in perovskite oxides for water‐splitting electrocatalysis,including their developmental history,compositional and structural diversities,structure‐performance correlations,activity descriptors,catalytic mechanisms,and structural evolutions.We emphasize the importance of in situ characterization techniques for monitoring dynamic structural information and identifying important active species.Finally,we outline the opportunities and challenges of perovskite oxides for practical applications in water electrolysis,with the aim of providing further directions for exploring next‐generation electrocatalysts.展开更多
Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stabilit...Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stability of air electrodes exposed to concentrated vapor under operating conditions. Herein, we report a high-entropy air electrode with the composition BaCo_(0.2)Fe_(0.2)Zr_(0.2)Sn_(0.2)Pr_(0.2)O_(3-δ)(BCFZSP), which shows integrated electronic, protonic and oxygenic conduction in a single perovskite phase and excellent structural stability in concentrated steam. Such triple conduction can spread the electrochemically active sites of the air electrode to the overall electrode surface, thus optimizing the kinetics of the oxygen reduction and evolution reactions(0.448 Ω cm^(2) of polarization resistance at 550℃). As-prepared RPCCs with a BCFZSP air electrode at 600℃ achieved a peak power density of 0.68 W/cm^(2) in fuel-cell mode and a current density of 0.92 A/cm^(2) under a 1.3 V applied voltage in electrolysis mode. More importantly, the RPCCs demonstrate an encouragingly high stability during 120 h of reversible switching between the fuelcell and electrolysis modes. Given their excellent performance, high-entropy perovskites can be promising electrode materials for RPCCs.展开更多
Volatile organic compounds are a kind of important indoor and outdoor air pollutants.In recent years,more and more attention has been paid to the ways of volatile organic compound elimination because of its potential ...Volatile organic compounds are a kind of important indoor and outdoor air pollutants.In recent years,more and more attention has been paid to the ways of volatile organic compound elimination because of its potential long-term effects on human health.Among the various available methods for volatile organic compound elimination,the catalytic combustion is the most attractive method due to its high efficiency,low cost,simple operation,and easy scale-up.Perovskite oxides,as a large family of metal oxides with their A-site mainly of lanthanide element and/or alkaline earth metal element and B-site of transition metal element,have been extensively investigated as active and stable catalysts for volatile organic compound removal reactions due to their abundant compositional elements,high thermal/chemical stability,and compositional/structural flexibility.The catalytic performance of perovskite oxides is strongly depended on its material composition,morphology,and surface/bulk properties,while the doping,tailored synthesis route,and composite construction may have a significant effect on the bulk(oxygen vacancy concentration,lattice structure),surface(oxygen species,defect)properties,and particulate morphology,consequently the catalytic activity and stability for volatile organic compound removal.Herein,a comprehensive review about the recent advances in perovskite oxides for volatile organic compound elimination reactions based on catalytic combustion is presented from different aspects with a special emphasis on the material design strategies,such as compositional tuning,morphology control,nanostructure building,hybrid construction,and surface modification.At last,some perspectives are presented on the development and design of perovskite oxide-based catalysts for volatile organic compound removal applications by highlighgting the critical issues and challenges.展开更多
The growth of electrochemically inert segregation layers on the surface of solid oxide fuel cell cathodes has become a bottleneck restricting the development of perovskite-structured oxygen reduction catalysts.Here,we...The growth of electrochemically inert segregation layers on the surface of solid oxide fuel cell cathodes has become a bottleneck restricting the development of perovskite-structured oxygen reduction catalysts.Here,we report a new discovery in which enriched Ba and Fe ions on the near-surface of Nd_(1/2)Ba_(1/2)Co_(1/3)Fe_(1/3)Mn_(1/3)O_(3-δ)spontaneously agglomerate into dispersed Ba_(5)Fe_(2)O_(8) nanoparticles and maintain a highly active and durable perovskite structure on the surface.This unique surface selfcleaning phenomenon is related to the low average potential energy of Ba_(5)Fe_(2)O_(8),which is grown on the near-surface layer.The electrochemically inert Ba_(5)Fe_(2)O_(8) segregation layer on the near-surface of the perovskite catalyst achieves self-cleaning by regulating the formation energy of enriched metal oxides.This self-cleaned perovskite surface exhibits an ultrafast oxygen exchange rate,high catalytic activity for the oxygen reduction reaction,and good adaptability to the actual working conditions of solid oxide fuel cell stacks.This study paves a new way for overcoming the stubborn problem of perovskite catalyst surface deactivation and enriches the scientific knowledge of surface catalysis.展开更多
Magnetic properties were investigated for the rare-earth 3d-transition metal oxides with the perovskite structure. Intriguing magnetic phenomena were reviewed for a few systems:magnetization peak effect in the titanat...Magnetic properties were investigated for the rare-earth 3d-transition metal oxides with the perovskite structure. Intriguing magnetic phenomena were reviewed for a few systems:magnetization peak effect in the titanates, magnetization reversal in the chromites and metallic ferromagnetism in the cobaltites. The results suggest an important role of the rare-earth ions for the magnetic properties of such complex oxides.展开更多
Crystalline perovskite oxides are regarded as promising electrocatalysts for water electrolysis,particularly for anodic oxygen evolution reactions,owing to their low cost and high intrinsic activity.Perovskite oxides ...Crystalline perovskite oxides are regarded as promising electrocatalysts for water electrolysis,particularly for anodic oxygen evolution reactions,owing to their low cost and high intrinsic activity.Perovskite oxides with noncrystalline or amorphous characteristics also exhibit promising electrocatalytic performance toward electrochemical water splitting.In this review,a fundamental understanding of the characteristics and advantages of crystalline,noncrystalline,and amorphous perovskite oxides is presented.Subsequently,recent progress in the development of advanced electrocatalysts for water electrolysis by engineering and breaking the crystallinity of perovskite oxides is reviewed,with a special focus on the underlying structure–activity relationships.Finally,the remaining challenges and unsolved issues are presented,and an outlook is briefly proposed for the future exploration of next-generation water-splitting electrocatalysts based on perovskite oxides.展开更多
Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- t...Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- tion（XRD）, high-resolution transmission electron microscopy（HRTEM）, and conductive atomic force microscopy （C-AFM） at room temperature. The thin films with thickness ranged from 100 nm to 300 nm basically show cubic structures with a=0.3886 nm, the same as that of the raw material used, but the structures are highly modulated. C-AFM results revealed that the atomic scale p-n junction feature of the thin films was the same as that of the single crystals. The preparation of the thin films thus further confirms the possibility of their application extending from micrometer-sized single crystals to macroscopic thin film.展开更多
基金financially supported by the National Natural Science Foundation of China (U2032157, 22209061)the Natural Science Foundation of Jiangsu Province (BK20201425)the Start-up Fund for Senior Talents in Jiangsu University(21JDG060)。
文摘Polycrystalline perovskite oxide particles are promising candidates for cathode materials in solid oxide fuel cells.However,their limited activity and stability pose significant challenges for practical applications.In this study,we demonstrate a novel approach to achieve both high activity and durability in a PrBaCo_(2)O_(5+δ) catalyst through a simple epitaxial layer growth strategy.We found that an amorphous precursor of the highly durable catalyst SmBa_(0.5)Ca_(0.5)CoCuO_(5+δ) can spontaneously adhere to the surface of PrBaCo_(2)O_(5+δ) particles.Upon heat treatment,it grows along the perovskite lattice,forming a heteroepitaxial layer with just a few atomic layers thickness.This heterostructure enhances the operational stability of PrBaCo_(2)O_(5+δ) transforming a 78% decrease over 100 h into a 7% increase.After 100 h,the power output density of the cell with the modified sample is more than 500% higher than that of unmodified PrBaCo_(2)O_(5+δ.)This work presents a new strategy for fabricating heteroepitaxial layers on polycrystalline ceramic catalysts and introduces a pioneering approach for developing high-performance oxygen reduction catalysts and related materials.
基金financially supported by the National Key Research and Development Program(Nos.2022YFB2502104 and 2022YFA1602700)the Key Research and Development Program of Jiangsu Provincial Department of Science and Technology of China(No.BE2022332)+4 种基金the Jiangsu Carbon Peak Carbon Neutralization Science and Technology Innovation Special Fund(No.BE2022605)the National Natural Science Foundation of China(Nos.22109073,22379071)the DECRA program of Australian Research Council(No.DE230100357)the JSPS KAKENHI(No.JP23K13703)the Center for Computational Materials Science,Institute for Materials Research,Tohoku University for the use of MASAMUNE-IMR(202312-SCKXX-0203)。
文摘Perovskite oxides(ABO_(3))are thought to be promising electrocatalysts for oxygen evolution reaction(OER),but their specific surface area(SSA)is too low(usually<10 m^(2) g^(−1)).Developing advanced ABO_(3) electrocatalysts with high SSA and optimized structure is of great significance but remains a tremendous challenge.Herein,we propose a general strategy for fabrication of mesoporous perovskite oxide nanosheets(MPONs)with controllable atomic doping via self-sacrificial template-induced nanostructure modulation.A variety of MPONs including LaFeO_(3),A-site-doped LaFeO_(3)(A-LaFeO_(3),where A is Pr,Nd,Sm,Eu,or Gd)and B-site-doped LaFeO_(3)(B-LaFeO_(3),where B is Mn,Co,Ni,Cu,or Zn)have been achieved.Interestingly,it is discovered that the catalytic activities of A-LaFeO_(3) MPONs as OER catalysts are overall higher than those of B-LaFeO_(3) ones.Especially,the screened Eu-LaFeO_(3) MPONs only require a low overpotential of 267 mV at 10 mA cm^(−2),outperforming most reported perovskite oxides.The superior catalytic activity of Eu-LaFeO_(3) MPONs is attributed to their favorable porous structure,which increases the density of active sites,and enhanced lattice oxygen participation,which improves the intrinsic activity.This study provides guidance for the design and controlled synthesis of advanced rare-earth-doped MPONs with ultrahigh SSA for enhanced electrocatalysis.
基金supported by the National Natural Science Foundation of China(No.U22A20418,22075196)the Research Project Supported by Shanxi Scholarship Council of China(2022–050).
文摘The electrochemical nitrogen reduction reaction(NRR)under ambient conditions presents a promising approach for the eco-friendly and sustainable synthesis of ammonia,with a continuous emergence of potential electrocatalysts.However,the low solubility and limited diffusion of N_(2)significantly hinder the achievement of satisfactory performance.In this context,we report an effective strategy to enhance NRR activity by introducing a metal-organic framework(MOF)membrane,specifically MIL-53(Al),onto a perovskite oxide(LiNbO_(3)),denoted as LN@MIL-X(X=0.2,0.4 and 0.6).The MIL-53(Al)membrane selectively recognizes and concentrates N_(2)at the catalyst interface while simultaneously repelling water molecules,thereby inhibiting the hydrogen evolution reaction(HER).This ultrathin nanostructure significantly improves the NRR performance of LN@MIL-X compared to pristine LiNbO_(3).Notably,LN@MIL-0.4 exhibits a maximum NH_(3)yield of 45.25 mg h^(-1)mg_(cat.)^(-1)with an impressive Faradaic efficiency(FE)of 86.41%at-0.45 V versus RHE in 0.1 mol L^(-1)Na_(2)SO_(4).This work provides a universal strategy for the design and synthesis of perovskite oxide electrocatalysts,facilitating high-efficiency ammonia synthesis.
基金supported by the National Natural Science Foundation of China(No.22278203)The authors appreciate the support of Zhejiang Zheneng Technology and Environment Group Co.,Ltd’s project(No.TD-KJ-23-005:Methanation of carbon monoxide coupled with in-situ formed hydrogen in a low-temperature SOEC reactor).
文摘Proton ceramic fuel cell efficiently converts chemical energy into electrical energy,representing a pivotal component of future energy systems.However,its current performance is hindered by limitations in cathode and electrolyte materials,thereby impeding commercialization.Anion doping emerges as a promising strategy to enhance the electrochemical efficiency of perovskite-based cathodes and electrolytes.However,integrating this approach within a single-cell structure still requires further research.In this study,F-doped perovskite oxides BaCo_(0.4)Fe_(0.4)Zr_(0.1)Y_(0.1)O_(2.9-δ)F_(0.1)(BCFZYF)and BaZr_(0.1)Ce_(0.7)Y_(0.1)Yb_(0.1)O_(2.9-δ)F_(0.1)(BZCYYbF)were synthesized for use as the cathode and electrolyte,respectively,in proton ceramic fuel cells.Our findings demonstrate that F-doped perovskite oxides exhibit superior electrochemical performance and enhanced structural stability.Furthermore,doping both electrodes and electrolytes with F ions improves their interfacial compatibility.The cell configuration BCFZYF|BZCYYbF|Ni-BZCYYbF achieved a peak power density of 998 mW·cm^(−2)at 650℃using H_(2)as fuel,and it maintained stable operation for over 400 h at 550℃with a current density of 400 mA·cm^(−2).This research underscores an effective strategy for enhancing the performance and durability of proton ceramic fuel cells.
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National Natural Science Foundation of China(21761162016)Key R&D Planning Research Project of Liaoning Province(2107229008)Science and Technology Research Planning Project of Shenyang City(Z17-5-056)。
文摘The disordered macroporous-mesoporous La_(1-x)Ce_(x)CoO_(3)catalysts were prepared by complexcombustion method with ethylene glycol as complexing agent at relatively low calcination temperature.The samples were characterized by means of X-ray diffraction,N_(2)adsorption-ndash;desorption,Xray photoelectron spectroscopy,transmission electron microscopy,hydrogen temperature-programmed reduction and soot temperature-programmed reduction,and so on.The results show that the use of complexing agent and relatively low calcination temperature increase the specific surface area of the catalyst and have abundant pore structure.The Ce ions introduced into lattice of LaCoO_(3)mainly exist in the form of tetravalent.At the same time,Ce ions enhance the redox performance of the catalyst and the mobility of active oxygen species,which enhances the catalytic activity of the catalyst for soot combustion.The results of activity test show that La0.9Ce0.1CoO3 catalyst exhibits the highest activity in the absence of NO and NO2,and its T10,T50 and T90 are 371,444,and 497℃,respectively.At the same time,a possible reaction mechanism is proposed in this study based on the turnover frequency(TOF)calculated by isothermal anaerobic titrations,XPS and XRD results.
文摘In this paper, the partial oxidation of methane to synthesis gas using lattice oxygen of La1- SrxMO3-λ (M=Fe, x Mn) perovskite oxides instead of molecular oxygen was investigated. The redox circulation between 11% O2/Ar flow and 11% CH4/He flow at 900℃ shows that methane can be oxidized to CO and H2 with a selectivity of over 90.7% using the lattice oxygen of La1- SrxFeO3-λ (x≤0.2) perovskite oxides in an appropriate reaction condition, while the lost lattice x oxygen can be supplemented by air re-oxidation. It is viable for the lattice oxygen of La1- SrxFeO3-λ (x≤0.2) perovskite x oxides instead of molecular oxygen to react with methane to synthesis gas in the redox mode.
基金Project supported by the Ministry of Education Blue Fire Program(XZJH201717)。
文摘Magnesia modified LaCoO3 was prepared by a facile one-step sol-gel method and used for removal of dilute methane.Compared with the conventional doping technique,the obtained LaCoO3@MgO-x exhibits pseudo core-shell structure and shows superior catalytic activity.The methane conversion exceeds90%at 532℃on LaCoO3@MgO-0.1,while only 60%of methane is conversed using the doped perovskite LaCo0.9Mg0.1O3.The high catalytic performance of LaCoO3@MgO-0.1 is mainly attributed to the adjustment of surface acid-base properties by the MgO shell structure.According to density functional theory(DFT)calculation,the methane is more likely to be adsorbed and cracked on LaCoO3@MgO-0.1.The in situ DRIFTS shows that CH3-O-CH3 intermediate specie is formed.The pseudo core-shell structure also enhances the stability and the LaCoO3@MgO-0.1 maintains high activity after working for 100 h.The above results demonstrate that surface modification by magnesia is an effective strategy for improving LaCoO3 catalytic performance.
基金Project supported by the National Natural Science Foundation of China(21671147)Natural Science Foundation of Shanxi Province(201901D211117)Coal Bed Methane Joint Foundation of Shanxi Province(2016012004).
文摘A series of BaCe0_(3)modified with different rare earth elements(La,Y,Pr)were synthesized by coprecipitation and calcination and the effect of rare earth elements for catalytic ammonia synthesis under mild conditions was studied.The ammonia synthesis performance tests show that 2.5%Ru/BaCe_(0.9)La_(0.1)O_(3-δ)catalyst(All the percentages of Ru in this article are in mass fraction)exhibits the highest ammonia synthesis rate(34 mmol/(g·h))at 3 MPa,450℃,and no sign of deactivation after 100 h of reaction.H_(2)-TPR and XPS analyses indicate that the introduction of La increases the amount of oxygen vacancies of the catalyst,which is beneficial to increasing the electron density of Ru surface.HRTEM analysis shows that the Ru particle size is reduced greatly after La is introduced,which facilitates the catalyst generating more Bs-type sites(active sites of Ru species for N=N dissociation).CO_(2)-TPD analysis indicates that BaCe_(0.9)La_(0.1)O_(3-δ)has stronger basicity,which promotes electrons transfer from support to Ru.This work provides an effective method for design and synthesis of Ru-based multi-element composite perovskite oxide catalysts.
基金the Chinese Natural Science Foundation(Project No.20306016)
文摘Comparison of LaFeO3, La0.8Sr0.2FeO3, and La0.8Sr0.2Fe0.9CO0.1O3 perovskite oxides as oxygen carrier for partial oxidation of methane in the absence of gaseous oxygen was investigated by continuous flow reaction and sequential redox reaction, Methane was oxidized to syngas with high selectivity by oxygen species of perovskite oxides in the absence of gaseous oxygen. The sequential redox reaction revealed that the structural stability and continuous oxygen supply in redox reaction decreased over La0.8Sr0.2Fe0.9Co0. 1O3 oxide, while LaFeO3 and La0.8Sr0.2FeO3 exhibited excellent structural stability and continuous oxygen supply.
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supported by the National Natural Science Foundation of China (51877173)the Key R&D Project of Shaanxi Province (2023-YBGY-057)+1 种基金the State Key Laboratory of Electrical Insulation and Power Equipment (EIPE22314, EIPE22306)the Natural Science Basic Research Program of Shaanxi (2023-JC-QN-0483)。
文摘Solid oxide electrolysis cell(SOEC) could be a potential technology to afford chemical storage of renewable electricity by converting water and carbon dioxide.In this work,we present the Ni-doped layered perovskite oxides,(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2) with n=5,8,and 12(LSTNn) for application as catalysts of CO_(2) electrolysis with the exsolution of Ni nanoparticles through a simple in-situ growth method.It is found that the density,size,and distribution of exsolved Ni nanoparticles are determined by the number of n in LSTNn due to the different stack structures of TiO_6 octahedra along the c axis.The Ni doping in LSTNn significantly improved the electrochemical activity by increasing oxygen vacancies,and the Ni metallic nanoparticles afford much more active sites.The results show that LSTNn cathodes can successfully be manipulated the activity by controlling both the n number and Ni exsolution.Among these LSTNn(n=5,8,and 12),LSTN8 renders a higher activity for electrolysis of CO_(2) with a current density of 1.50A cm^(-2)@2.0 V at 800℃ It is clear from these results that the number of n in(La_(4)Sr_(n-4))_(0.9)Ti_(0.9n)Ni_(0.1n)O_(3n+2)with Ni-doping is a key factor in controlling the electrochemical performance and catalytic activity in SOEC.
文摘The urgent need for decarbonized hydrogen production to achieve carbon‐neutral targets has highlighted the critical role of water electrolysis technology in advancing sustainability in various fields.However,the gap in economic efficiency between green hydrogen,generated by renewable electricity‐driven water electrolysis,and gray hydrogen,generated by the consumption of fossil fuels,remains a challenge.Therefore,the exploration of cost‐effective,active,and stable electrocatalysts toward water‐splitting reactions is essential.Owing to their high‐tolerance crystal structures,flexible elemental compositions,and adjustable electronic properties,perovskite oxides provide a vast material library for customizing next‐generation electrocatalysts.Additionally,perovskite oxides are increasingly being developed into ideal model catalysts for unraveling scientific laws and theories,emphasizing the significance of investigating their important characteristics(e.g.,structure‐performance relationship,electronic property regulation,catalytic mechanism,and dynamic structural evolution).This review summarizes recent advances in perovskite oxides for water‐splitting electrocatalysis,including their developmental history,compositional and structural diversities,structure‐performance correlations,activity descriptors,catalytic mechanisms,and structural evolutions.We emphasize the importance of in situ characterization techniques for monitoring dynamic structural information and identifying important active species.Finally,we outline the opportunities and challenges of perovskite oxides for practical applications in water electrolysis,with the aim of providing further directions for exploring next‐generation electrocatalysts.
基金financially supported by the National Natural Science Foundation of China (Nos. 22078022, 22178023, 22179007)China Postdoctoral Science Foundation (No. 2021M690379)。
文摘Reversible protonic ceramic cells(RPCCs) show great potential as new-generation energy conversion and storage devices. However, the mature development of RPCCs is seriously hindered by the inactivity and poor stability of air electrodes exposed to concentrated vapor under operating conditions. Herein, we report a high-entropy air electrode with the composition BaCo_(0.2)Fe_(0.2)Zr_(0.2)Sn_(0.2)Pr_(0.2)O_(3-δ)(BCFZSP), which shows integrated electronic, protonic and oxygenic conduction in a single perovskite phase and excellent structural stability in concentrated steam. Such triple conduction can spread the electrochemically active sites of the air electrode to the overall electrode surface, thus optimizing the kinetics of the oxygen reduction and evolution reactions(0.448 Ω cm^(2) of polarization resistance at 550℃). As-prepared RPCCs with a BCFZSP air electrode at 600℃ achieved a peak power density of 0.68 W/cm^(2) in fuel-cell mode and a current density of 0.92 A/cm^(2) under a 1.3 V applied voltage in electrolysis mode. More importantly, the RPCCs demonstrate an encouragingly high stability during 120 h of reversible switching between the fuelcell and electrolysis modes. Given their excellent performance, high-entropy perovskites can be promising electrode materials for RPCCs.
基金supported by the National Natural Science Foundation of China(Project No.21908106 and 21878158)the Jiangsu Natural Science Foundation(Project No.BK20190682)+2 种基金the Program for Jiangsu Specially Appointed Professorsthe Funding from State Key Laboratory of Materials-Oriented Chemical Engineering(Project No.ZK201808)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Volatile organic compounds are a kind of important indoor and outdoor air pollutants.In recent years,more and more attention has been paid to the ways of volatile organic compound elimination because of its potential long-term effects on human health.Among the various available methods for volatile organic compound elimination,the catalytic combustion is the most attractive method due to its high efficiency,low cost,simple operation,and easy scale-up.Perovskite oxides,as a large family of metal oxides with their A-site mainly of lanthanide element and/or alkaline earth metal element and B-site of transition metal element,have been extensively investigated as active and stable catalysts for volatile organic compound removal reactions due to their abundant compositional elements,high thermal/chemical stability,and compositional/structural flexibility.The catalytic performance of perovskite oxides is strongly depended on its material composition,morphology,and surface/bulk properties,while the doping,tailored synthesis route,and composite construction may have a significant effect on the bulk(oxygen vacancy concentration,lattice structure),surface(oxygen species,defect)properties,and particulate morphology,consequently the catalytic activity and stability for volatile organic compound removal.Herein,a comprehensive review about the recent advances in perovskite oxides for volatile organic compound elimination reactions based on catalytic combustion is presented from different aspects with a special emphasis on the material design strategies,such as compositional tuning,morphology control,nanostructure building,hybrid construction,and surface modification.At last,some perspectives are presented on the development and design of perovskite oxide-based catalysts for volatile organic compound removal applications by highlighgting the critical issues and challenges.
基金financially supported by the National Natural Science Foundation of China (U2032157)the Natural Science Foundation of Jiangsu Province (BK20201425)。
文摘The growth of electrochemically inert segregation layers on the surface of solid oxide fuel cell cathodes has become a bottleneck restricting the development of perovskite-structured oxygen reduction catalysts.Here,we report a new discovery in which enriched Ba and Fe ions on the near-surface of Nd_(1/2)Ba_(1/2)Co_(1/3)Fe_(1/3)Mn_(1/3)O_(3-δ)spontaneously agglomerate into dispersed Ba_(5)Fe_(2)O_(8) nanoparticles and maintain a highly active and durable perovskite structure on the surface.This unique surface selfcleaning phenomenon is related to the low average potential energy of Ba_(5)Fe_(2)O_(8),which is grown on the near-surface layer.The electrochemically inert Ba_(5)Fe_(2)O_(8) segregation layer on the near-surface of the perovskite catalyst achieves self-cleaning by regulating the formation energy of enriched metal oxides.This self-cleaned perovskite surface exhibits an ultrafast oxygen exchange rate,high catalytic activity for the oxygen reduction reaction,and good adaptability to the actual working conditions of solid oxide fuel cell stacks.This study paves a new way for overcoming the stubborn problem of perovskite catalyst surface deactivation and enriches the scientific knowledge of surface catalysis.
文摘Magnetic properties were investigated for the rare-earth 3d-transition metal oxides with the perovskite structure. Intriguing magnetic phenomena were reviewed for a few systems:magnetization peak effect in the titanates, magnetization reversal in the chromites and metallic ferromagnetism in the cobaltites. The results suggest an important role of the rare-earth ions for the magnetic properties of such complex oxides.
基金Program for Jiangsu Specially-AppointedProfessors。
文摘Crystalline perovskite oxides are regarded as promising electrocatalysts for water electrolysis,particularly for anodic oxygen evolution reactions,owing to their low cost and high intrinsic activity.Perovskite oxides with noncrystalline or amorphous characteristics also exhibit promising electrocatalytic performance toward electrochemical water splitting.In this review,a fundamental understanding of the characteristics and advantages of crystalline,noncrystalline,and amorphous perovskite oxides is presented.Subsequently,recent progress in the development of advanced electrocatalysts for water electrolysis by engineering and breaking the crystallinity of perovskite oxides is reviewed,with a special focus on the underlying structure–activity relationships.Finally,the remaining challenges and unsolved issues are presented,and an outlook is briefly proposed for the future exploration of next-generation water-splitting electrocatalysts based on perovskite oxides.
基金Supported by the National Natural Science Foundation of China(No.90922034)
文摘Thin films of perovskite manganese oxide Lao.66Ca0.29K0.05MnO3（LCKMO） on Au/ITO（ITO=indium tin oxide） substrates were prepared by off-axis radio frequency magnetron sputtering and characterized by X-ray diffrac- tion（XRD）, high-resolution transmission electron microscopy（HRTEM）, and conductive atomic force microscopy （C-AFM） at room temperature. The thin films with thickness ranged from 100 nm to 300 nm basically show cubic structures with a=0.3886 nm, the same as that of the raw material used, but the structures are highly modulated. C-AFM results revealed that the atomic scale p-n junction feature of the thin films was the same as that of the single crystals. The preparation of the thin films thus further confirms the possibility of their application extending from micrometer-sized single crystals to macroscopic thin film.
