Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been...Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been widely studied as an active cathode but still suffer from serious detrimental segregations.To enhance the cathode stability,a PBCC derived A-site medium-entropy Pr_(0.6)La_(0.1)Nd_(0.1)Sm_(0.1)Gd_(0.1)Ba_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(ME-PBCC)oxide was prepared and its segregation behaviors were investigated under different conditions.Compared with initial PBCC oxide,the segregations of BaO and Co_(3)O_(4)on the surface of ME-PBCC material are significantly suppressed,especially for Co_(3)O_(4),which is attributed to its higher configuration entropy.Our results also confirm the improved electrochemical performance and structural stability of ME-PBCC material,enabling it as a promising cathode for SOFCs.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
Several compounds of rare earth complex oxides containing manganese and titanium were synthesized in Ar, and their crystal structures were analyzed by powder X-ray diffraction data and Rietveld method. Structures of A...Several compounds of rare earth complex oxides containing manganese and titanium were synthesized in Ar, and their crystal structures were analyzed by powder X-ray diffraction data and Rietveld method. Structures of A0.67Ln0.33 Mn0.33Ti0.6703（A = Ca or Sr and Ln = rare earth） were found to have orthorhombic symmetry with the space group Pnrna, and their interatomic distances and bond angles were obtained. This space group was also derived from electron microscopic study. Electrical conductivity of Cao.67Ln0.33Mn0.33Ti0.6703 for several rare earth elements showed a semiconducting property with the activation energy of 0.4 eV. Some of these compounds of the strontium system show the antiferromagnetic properties below 10 K.展开更多
Single crystals of 0.91Pb（Zn1/3Nb2/3）O3-0.09PbTiO3, SrTiO3 and BaTiO3, and ceramic pellets of CaCu3Ti4Oi2 and BiFeO3 have been studied and compared through electrochemical hydrogen charging, in which the oxides were...Single crystals of 0.91Pb（Zn1/3Nb2/3）O3-0.09PbTiO3, SrTiO3 and BaTiO3, and ceramic pellets of CaCu3Ti4Oi2 and BiFeO3 have been studied and compared through electrochemical hydrogen charging, in which the oxides were coated with silver electrodes to electrolyze water as the cathode. Great diversity has been observed in the stability of the oxides： 0.91Pb（Zn1/3Nb2/3）O3- 0,09PbTiO3 was quickly decomposed; hydrogen could enter the lattice of the other four oxides, but their properties were influenced at extremely different speeds. Such a great diversity in stability against hydrogen among perovskite-type oxides highlights the importance of reliability study over functional oxides materials.展开更多
The magnetic functional materials play a particularly important role in our modern society and daily life.The magnetocaloric effect(MCE)is at the basis of a solid state magnetic refrigeration(MR)technology which may e...The magnetic functional materials play a particularly important role in our modern society and daily life.The magnetocaloric effect(MCE)is at the basis of a solid state magnetic refrigeration(MR)technology which may enhance the efficiency of cooling systems,both for room temperature and cryogenic appli-cations.Despite numerous experimental and theoretical MCE studies,commercial MR systems are still at developing stage.Designing magnetic solids with outstanding magnetocaloric performances remains therefore a most urgent task.Herein,recent progresses on characterizing the crystal structure,magnetic properties and cryogenic MCE of rare earths(RE)-based RE_(2)TMTM’O_(6)double perovskite(DP)oxides,where TM and TM’are different 3d transition metals,are summarized.Some Gd-based DP oxides are found to exhibit promising cryogenic magnetocaloric performances which make them attractive for active MR ap-plications.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
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
The requirement for a sustainable and renewable energy has inspired substantial interests in designing and developing earth-abundant and high-effectiveness electrocatalysts/electrodes for fuel cells and metal-air batt...The requirement for a sustainable and renewable energy has inspired substantial interests in designing and developing earth-abundant and high-effectiveness electrocatalysts/electrodes for fuel cells and metal-air batteries,in which oxygen reduction reaction(ORR)plays a crucial role.Perovskite oxides have acquired rapid attention as ORR electrocatalysts to replace noble-metal-based catalysts owing to their intrinsic electrocatalytic activity,compositional and structural flexibility.Herein,we report a new Sc and P co-doped perovskite oxide(La0.8Sr0.2Mn0.95Sc0.025P0.025O3-δ,LSMSP)as an active and robust electrocatalyst for the ORR in an alkaline solution.LSMSP electrocatalyst shows superior ORR activity and stability than those of pristine La0.8Sr0.2MnO3-δ(LSM),Sc-doped LSM and P-doped LSM due to the optimized average valence of Mn ions,the large surface area,the smaller particle size and the synergetic effect introduced by the co-doping.Moreover,compared to the benchmark Pt/C electrocatalyst,LSMSP electrocatalyst displays comparable ORR activity and superior durability.These above results suggest that the co-doping strategy of Sc and P into perovskites is a useful method to design high-performance electrocatalysts for the ORR,which can be used in other electrocatalysis-based applications.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
Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supp...Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supported catalysts in catalytic methane combustion due to excellent hydrothermal stability and sulfur resistance. Recently, the emergence of nanostructured perovskite oxides（such as threedimensional ordered nanostructure, nano-array structure） with outstanding catalytic activity has further driven methane catalytic combustion research into spotlight. In this review, we summarize the recent development of nanostructured perovskite oxide catalysts for methane combustion, and shed some light on the rational design of high efficient nanostructured perovskite catalysts via lattice oxygen activation,lattice oxygen mobility and materials morphology engineering. The emergent issues needed to be addressed on perovskite catalysts were also proposed.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 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
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
Double-perovskite type oxide LaSrFeCoO（LSFCO） was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Two different oxidation routes,steam-oxidat...Double-perovskite type oxide LaSrFeCoO（LSFCO） was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Two different oxidation routes,steam-oxidation and steam-air-stepwise-oxidation, were applied to investigate the recovery behaviors of the lattice oxygen in the oxygen carrier. The characterizations of the oxide were determined by X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, hydrogen temperature-programmed reduction（H-TPR） and scanning electron microscopy（SEM）. The fresh sample LSFCO exhibits a monocrystalline perovskite structure with cubic symmetry and high crystallinity, except for a little impurity phase due to the antisite defect of Fe/Co disorder. The deconvolution distribution of XPS patterns indicated that Co,and Fe are predominantly in an oxidized state(Feand Fe) and(Coand Co), while O 1s exists at three species of lattice oxygen, chemisorbed oxygen and physical adsorbed oxygen. The double perovskite structure and chemical composition recover to the original state after the steam and air oxidation, while the Co ion cannot incorporate into the double perovskite structure and thus form the CoO just via individual steam oxidation. In comparison to the two different oxidation routes, the sample obtained by steam-oxidation exhibits even higher CHconversion, CO and Hselectivity and stronger hydrogen generation capacity.展开更多
The double perovskite oxides LaSrFeMo0.9Co0.1O6 was prepared by co-precipitation method and sol-gel method. The title catalysts were calcined at 800°C and characterized by XRD H2-TPR, SEM and TG-DTA techniques. T...The double perovskite oxides LaSrFeMo0.9Co0.1O6 was prepared by co-precipitation method and sol-gel method. The title catalysts were calcined at 800°C and characterized by XRD H2-TPR, SEM and TG-DTA techniques. The catalytic activity was evaluated for methane combustion. The specific surface area of them was calculated by BET model. The samples exhibit significant catalytic activity for methane combustion at 800°C. Upon calcination at 800°C, the LaSrFeMo0.9Co0.1O6 prepared by sol-gel method retains a specific surface area of 24 m2.g-1 and shows an excellent activity for methane combustion (the conversion of 10% and 90% are obtained at 505°C and 660°C, respectively).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
The performance of La2NiO4 perovskite catalysts,prepared using a citric acid complexation method,for the steam reforming of ethanol was studied.The catalysts were characterized by X-ray diffractometry(XRD),specific su...The performance of La2NiO4 perovskite catalysts,prepared using a citric acid complexation method,for the steam reforming of ethanol was studied.The catalysts were characterized by X-ray diffractometry(XRD),specific surface area measurements(BET),thermogravimetric analysis(TGA)and scanning electron microscopy(SEM).The experimental results show that the calcination temperature and the amount of citric acid(CA)have a significant influence on the characteristics of the catalysts and their catalytic activity.Among the catalysts tested,the La2NiO4 catalyst calcined at 700 ℃withn(La):n(Ni):n(CA)of 2:1:3 exhibits the best activity and excellent stability as well as very low coke formation.展开更多
A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij...A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems.展开更多
基金Project supported by the National Natural Science Foundation of China(22279025,21773048,52302119)the Fundamental Research Funds for the Central Universities(2023FRFK06005,HIT.NSRIF202204)。
文摘Cation segregation on cathode surfaces plays a key role in determining the activity and operational stability of solid oxide fuel cells(SOFCs).The double perovskite oxide PrBa_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(PBCC)has been widely studied as an active cathode but still suffer from serious detrimental segregations.To enhance the cathode stability,a PBCC derived A-site medium-entropy Pr_(0.6)La_(0.1)Nd_(0.1)Sm_(0.1)Gd_(0.1)Ba_(0.8)Ca_(0.2)Co_(2)O_(5+δ)(ME-PBCC)oxide was prepared and its segregation behaviors were investigated under different conditions.Compared with initial PBCC oxide,the segregations of BaO and Co_(3)O_(4)on the surface of ME-PBCC material are significantly suppressed,especially for Co_(3)O_(4),which is attributed to its higher configuration entropy.Our results also confirm the improved electrochemical performance and structural stability of ME-PBCC material,enabling it as a promising cathode for SOFCs.
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Foundation ite ms:Project supported bythe Grant-in-Aidfor Scientific Research (C) (18560662) bythe Japan Societyfor the Promotion of Science
文摘Several compounds of rare earth complex oxides containing manganese and titanium were synthesized in Ar, and their crystal structures were analyzed by powder X-ray diffraction data and Rietveld method. Structures of A0.67Ln0.33 Mn0.33Ti0.6703（A = Ca or Sr and Ln = rare earth） were found to have orthorhombic symmetry with the space group Pnrna, and their interatomic distances and bond angles were obtained. This space group was also derived from electron microscopic study. Electrical conductivity of Cao.67Ln0.33Mn0.33Ti0.6703 for several rare earth elements showed a semiconducting property with the activation energy of 0.4 eV. Some of these compounds of the strontium system show the antiferromagnetic properties below 10 K.
基金Supported by the National Natural Science Foundation of China (50772077)
文摘Single crystals of 0.91Pb（Zn1/3Nb2/3）O3-0.09PbTiO3, SrTiO3 and BaTiO3, and ceramic pellets of CaCu3Ti4Oi2 and BiFeO3 have been studied and compared through electrochemical hydrogen charging, in which the oxides were coated with silver electrodes to electrolyze water as the cathode. Great diversity has been observed in the stability of the oxides： 0.91Pb（Zn1/3Nb2/3）O3- 0,09PbTiO3 was quickly decomposed; hydrogen could enter the lattice of the other four oxides, but their properties were influenced at extremely different speeds. Such a great diversity in stability against hydrogen among perovskite-type oxides highlights the importance of reliability study over functional oxides materials.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52171174 and 91963123)the Ten Thousand Talents Plan of Zhejiang Province(No.2018R52003)the Fundamental Research Funds for the Provincial University of Zhejiang(No.GK199900299012-022).
文摘The magnetic functional materials play a particularly important role in our modern society and daily life.The magnetocaloric effect(MCE)is at the basis of a solid state magnetic refrigeration(MR)technology which may enhance the efficiency of cooling systems,both for room temperature and cryogenic appli-cations.Despite numerous experimental and theoretical MCE studies,commercial MR systems are still at developing stage.Designing magnetic solids with outstanding magnetocaloric performances remains therefore a most urgent task.Herein,recent progresses on characterizing the crystal structure,magnetic properties and cryogenic MCE of rare earths(RE)-based RE_(2)TMTM’O_(6)double perovskite(DP)oxides,where TM and TM’are different 3d transition metals,are summarized.Some Gd-based DP oxides are found to exhibit promising cryogenic magnetocaloric performances which make them attractive for active MR ap-plications.
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.
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financially supported by the National Natural Science Foundation of China(Nos.21576135 and 21706129)the Youth Fund of Jiangsu Province(No.BK20150945)+2 种基金Program for Jiangsu Specially-Appointed Professorsthe Funding from State Key Laboratory of Materials-Oriented Chemical Engineering(No.ZK201808)the financial support of the Australian Research Council.
文摘The requirement for a sustainable and renewable energy has inspired substantial interests in designing and developing earth-abundant and high-effectiveness electrocatalysts/electrodes for fuel cells and metal-air batteries,in which oxygen reduction reaction(ORR)plays a crucial role.Perovskite oxides have acquired rapid attention as ORR electrocatalysts to replace noble-metal-based catalysts owing to their intrinsic electrocatalytic activity,compositional and structural flexibility.Herein,we report a new Sc and P co-doped perovskite oxide(La0.8Sr0.2Mn0.95Sc0.025P0.025O3-δ,LSMSP)as an active and robust electrocatalyst for the ORR in an alkaline solution.LSMSP electrocatalyst shows superior ORR activity and stability than those of pristine La0.8Sr0.2MnO3-δ(LSM),Sc-doped LSM and P-doped LSM due to the optimized average valence of Mn ions,the large surface area,the smaller particle size and the synergetic effect introduced by the co-doping.Moreover,compared to the benchmark Pt/C electrocatalyst,LSMSP electrocatalyst displays comparable ORR activity and superior durability.These above results suggest that the co-doping strategy of Sc and P into perovskites is a useful method to design high-performance electrocatalysts for the ORR,which can be used in other electrocatalysis-based applications.
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the financial support from the Recruitment Program of Global Young Experts Start-up Fundthe Program of Introducing Talents of Discipline to Universities of China(111 Program, No. B17019)
文摘Heterogeneous catalytic combustion provides a feasible technique for high efficient methane utilization.Perovskites ABO_3-type materials have received renewed attention as a potential alternative for noble metals supported catalysts in catalytic methane combustion due to excellent hydrothermal stability and sulfur resistance. Recently, the emergence of nanostructured perovskite oxides（such as threedimensional ordered nanostructure, nano-array structure） with outstanding catalytic activity has further driven methane catalytic combustion research into spotlight. In this review, we summarize the recent development of nanostructured perovskite oxide catalysts for methane combustion, and shed some light on the rational design of high efficient nanostructured perovskite catalysts via lattice oxygen activation,lattice oxygen mobility and materials morphology engineering. The emergent issues needed to be addressed on perovskite catalysts were also proposed.
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.
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(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The financial support of the National Natural Science Foundation of China(51406208,51406214)supported by the Science&Technology Research Project of Guangdong Province(2015A010106009)the support of Key Laboratory of Renewable Energy,Chinese Academy of Sciences(Y607j51001)
文摘Double-perovskite type oxide LaSrFeCoO（LSFCO） was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Two different oxidation routes,steam-oxidation and steam-air-stepwise-oxidation, were applied to investigate the recovery behaviors of the lattice oxygen in the oxygen carrier. The characterizations of the oxide were determined by X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, hydrogen temperature-programmed reduction（H-TPR） and scanning electron microscopy（SEM）. The fresh sample LSFCO exhibits a monocrystalline perovskite structure with cubic symmetry and high crystallinity, except for a little impurity phase due to the antisite defect of Fe/Co disorder. The deconvolution distribution of XPS patterns indicated that Co,and Fe are predominantly in an oxidized state(Feand Fe) and(Coand Co), while O 1s exists at three species of lattice oxygen, chemisorbed oxygen and physical adsorbed oxygen. The double perovskite structure and chemical composition recover to the original state after the steam and air oxidation, while the Co ion cannot incorporate into the double perovskite structure and thus form the CoO just via individual steam oxidation. In comparison to the two different oxidation routes, the sample obtained by steam-oxidation exhibits even higher CHconversion, CO and Hselectivity and stronger hydrogen generation capacity.
文摘The double perovskite oxides LaSrFeMo0.9Co0.1O6 was prepared by co-precipitation method and sol-gel method. The title catalysts were calcined at 800°C and characterized by XRD H2-TPR, SEM and TG-DTA techniques. The catalytic activity was evaluated for methane combustion. The specific surface area of them was calculated by BET model. The samples exhibit significant catalytic activity for methane combustion at 800°C. Upon calcination at 800°C, the LaSrFeMo0.9Co0.1O6 prepared by sol-gel method retains a specific surface area of 24 m2.g-1 and shows an excellent activity for methane combustion (the conversion of 10% and 90% are obtained at 505°C and 660°C, respectively).
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.
文摘The performance of La2NiO4 perovskite catalysts,prepared using a citric acid complexation method,for the steam reforming of ethanol was studied.The catalysts were characterized by X-ray diffractometry(XRD),specific surface area measurements(BET),thermogravimetric analysis(TGA)and scanning electron microscopy(SEM).The experimental results show that the calcination temperature and the amount of citric acid(CA)have a significant influence on the characteristics of the catalysts and their catalytic activity.Among the catalysts tested,the La2NiO4 catalyst calcined at 700 ℃withn(La):n(Ni):n(CA)of 2:1:3 exhibits the best activity and excellent stability as well as very low coke formation.
基金Project supported by the National Natural Science Foundation of China(U1662103,21673290)Beijing Natural Science Foundation(2182060).
文摘A series of three-dimensionally ordered macro-mesoporous(3DOMM)La1-xCaxFeO3(x=0-0.3)perovskite-type oxides were designed and successfully fabricated for the first time via a dual-template method.In which,PMMA and Brij-56 were employed as the hard template and soft template,respectively.It is found that 3 DOMM La1-xCaxFeO3 exhibits abundant wormlike mesoporous channels about 3 nm in diameter on macroporous skeleton walls.The excellent catalytic activity of soot combustion benefits from not only the well-designed hierarchical porous structure of catalyst,but also the redox electron pair of Fe3+/Fe4+induced by the doping of low-valent alkaline earth metal Ca to A-site of LaFeO3.3DOMM La0.8Ca0.2FeO3 exhibits superior catalytic performance for soot combustion,which shows T50 of396℃.It is 189℃lower than that without catalyst.A combination of structure and composition in the design of catalyst can be widely extended to other catalytic systems.
