“Three-in-one”cathode,achieved via B-site heavy-doping of transition elements(typically Co,Fe)into proton-conductive perovskite,holds promise for enhancing the performance of proton-conducting solid oxide fuel cell(...“Three-in-one”cathode,achieved via B-site heavy-doping of transition elements(typically Co,Fe)into proton-conductive perovskite,holds promise for enhancing the performance of proton-conducting solid oxide fuel cell(H-SOFC)operated below 650℃for electricity generation.However,its electrochemical behavior above 650℃,essential for improving the efficiency of H-SOFC for fuel conversion,remains insufficiently explored.It is still challenging to propose guidance for the design of“threein-one”cathode toward optimal H-SOFC performance below and above 650℃,with the prerequisite of gaining a comprehensive understanding of the roles of Co and Fe in determining the H-SOFC performance.This work is to address this challenge.Through theoretical/experimental studies,Co is identified to play a role in improving the oxygen reduction reaction(ORR)activity while Fe plays a role in facilitating the cathode/electrolyte interfacial proton conduction.Therefore,if the operating temperature is above 650℃,lowering the Co/Fe ratio in“three-in-one”cathode becomes crucial since the limiting factor shifts from ORR activity to proton conduction.Implementing this strategy,the SOFC using BaCo_(0.15)-Fe_(0.55)Zr_(0.1)Y_(0.1)Yb_(0.1)O_(3−δ)cathode achieves peak power densities of 1.67Wcm^(−2)under H-SOFC mode at 700℃and 2.32Wcm^(−2)under dual ion-conducting SOFC mode at 750℃,which are the highest reported values so far.展开更多
In this work,we present an innovative method for fabricating high-performance proton-conductive fuel cells(PCFCs)by combining magnetron sputtering and flashlight sintering(FLS)techniques.BaZr_(0.8)Y_(0.2)O_(3–δ)(BZY...In this work,we present an innovative method for fabricating high-performance proton-conductive fuel cells(PCFCs)by combining magnetron sputtering and flashlight sintering(FLS)techniques.BaZr_(0.8)Y_(0.2)O_(3–δ)(BZY20)electrolyte thin-films are successfully prepared by improving the crystallinity while maintaining the stoichiometry.All components of PCFC,Ni-YSZ anode,BZY20 electrolyte and Pt-GDC cathode are fabricated by sequentially sputtering them onto an AAO substrate.Electrolytic sintering is performed at 550 and 650 V conditions using FLS,effectively solving the Ba evaporation problem encountered in conventional thermal sintering methods.XRD analysis confirms that the perovskite structure is retained,and crystallinity is improved in the FLS samples.Furthermore,FE-SEM and EDS analyses confirm the uniform elemental distribution and consistent thickness of the FLS-treated electrolyte.An optimized PCFC unit cell with FLS-treated electrolyte exhibits a peak power density of 200.0 mW cm^(-2) at 500℃ and an ohmic resistance of 376.0 mΩ cm^(-2).These results suggest that the combination of magnetron sputtering and FLS techniques is a promising approach for fabricating highperformance thin-film PCFCs.展开更多
Ethylene(C_(2)H_(4))is a core raw material for the petrochemical industry.It is of economic and environmental significance to use C_(2)H_(6)as the fuel and proton-conducting solid oxide fuel cells(P-SOFC)as the reacto...Ethylene(C_(2)H_(4))is a core raw material for the petrochemical industry.It is of economic and environmental significance to use C_(2)H_(6)as the fuel and proton-conducting solid oxide fuel cells(P-SOFC)as the reactor to co-generate electricity and C_(2)H_(4).However,the large-sized Ni particles in the conventional Nicermet anode directly crack C_(2)H_(6);and oxide materials with a mild capability of breaking C-C bonds are generally limited to electrolyte-supported structures with high ohmic impedance.This research for the first time constructs an anode-supported cell using BZCY as the porous scaffold and impregnated double perovskite(PrBa)_(0.95)(Fe_(0.8)Ni_(0.2))_(1.8)Mo_(0.2)O_(6-δ)(PBFNM0.2)as the anode electrocatalysis.FeNi3 nanoparticles exsolve from PBFNM0.2 in H_(2) and uniformly distribute on the surface of perovskite substrate,acting as an active component for C_(2)H_(6)dehydrogenation and electrochemical performance enhancement.The cell with 30 wt%PBFNM0.2 impregnated anode showing a high power density of 508 and 386mW/cm^(2) with H_(2) and C_(2)H_(6)fuels,respectively;high C_(2)H_(6)conversion of 50.9%,C_(2)H_(4)selectivity of 92.1%,and C_(2)H_(4)yield of 46.9%are achieved at 750℃and 700mA/cm^(2),which outperforms all previously electrolyte-supported cells for co-generated electricity and ethylene.Moreover,the cell demonstrated excellent recoverability throughout three dehydrogenation-regeneration cycles.This work provides a practical way with broad application potential to create a novel anode-supported cell efficiently realizing the co-generation of electricity and C_(2)H_(4)from C_(2)H_(6).展开更多
To address the challenge of insufficient oxygen vacancies in proton-conducting solid oxide fuel cells(H-SOFC),transition metal elements were doped into the B site of lanthanum ferrite perovskite(ABO3)to enhance its ca...To address the challenge of insufficient oxygen vacancies in proton-conducting solid oxide fuel cells(H-SOFC),transition metal elements were doped into the B site of lanthanum ferrite perovskite(ABO3)to enhance its catalytic activity further.The Mo-doped La_(0.6)Sr_(0.4)Fe_(0.9)Ni_(0.1)O_(3-δ)(LSFNMx,x=0.05,0.1)powder was synthesized via the sol−gel method,and its crystal structure,conductivity,defect chemistry,and electrochemical performance as an H-SOFC cathode were investigated.The prepared material exhibited a hexagonal structure with the R-3c space group and demonstrates good chemical stability under simulated working conditions.Mo doping increased the surface concentration of oxygen vacancies,leading to the accelerated oxygen transportation.Consequently,the polarization resistance(Rpol)and activation energy(Ea)are reduced.Specifically,LSFNM0.05 showed the lowest polarization resistance(approximately 0.26Ω·cm^(2))at 700°C.LSFNM0.05 achieved a maximum power density of 484 mW/cm^(2)at this temperature,outperforming those of LSFN(353 mW/cm^(2))and LSFNM0.1(365 mW/cm^(2)).展开更多
A novel Zr-substituted polyoxometalate（POM） H2K3[Na6（H2O）9][Zr3Na3O3（H2O）3-（GeW9O（34））2]·12H2O（1） has been made under hydrothermal conditions. 1 was characterized by infrared spectrum, thermogravimetr...A novel Zr-substituted polyoxometalate（POM） H2K3[Na6（H2O）9][Zr3Na3O3（H2O）3-（GeW9O（34））2]·12H2O（1） has been made under hydrothermal conditions. 1 was characterized by infrared spectrum, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. Crystal data are： H（50）O（95）Na9K3Ge2Zr3W（1）8, hexagonal space group P63/mmc, a = 15.2251（6）, b = 15.2251（6）, c = 25.035（2） , V = 5025.7（6） 3, Z = 2, Dc = 3.716 mg/m3, μ = 21.648 mm（-1）, F（000） = 4726, the final R = 0.0259 and w R = 0.0647 for 1487 observed reflections with I 2σ（I）. Single-crystal X-ray structure analysis reveals that 1 exhibits a 3-dimensional framework structure based on Zr3Na3-substituted polyanions [Zr3Na3O3（H2O）3（GeW9O（34））2]（11-） and [Na6（H2O）9]（6＋） clusters building blocks. UV-Vis spectrum indicates that 1 is a wide-gap semiconductor. In addition, the proton-conducting property of 1 was also investigated.展开更多
The liquid citrate method was used to synthesize perovskite-type SrCe0.9 Y0.1O3-α powder. SrCe09Y01O3-α membranes were prepared from the powder by sintering at 1450℃ for 10 h. The reactions in the process of the he...The liquid citrate method was used to synthesize perovskite-type SrCe0.9 Y0.1O3-α powder. SrCe09Y01O3-α membranes were prepared from the powder by sintering at 1450℃ for 10 h. The reactions in the process of the heat treatment were studied by XRD and DSC/TG. The microstructure of the powder and the membrane was observed by SEM. The results indicate that the perovskite-type SrCe0.9Y0.1 O3-α can be synthesized at 1100℃. The particle size of the synthesized SrCe0.9Y0.1O3-α powder is less than 1μm. The powder can be densified at 1450℃.展开更多
In the global trend of vigorously developing hydrogen energy,proton-conducting solid oxide electrolysis cells(P-SOECs)have attracted significant attention due to their advantages of high efficiency and not requiring p...In the global trend of vigorously developing hydrogen energy,proton-conducting solid oxide electrolysis cells(P-SOECs)have attracted significant attention due to their advantages of high efficiency and not requiring precious metals.However,the application of P-SOECs faces challenges,particularly in developing high-performance anodes possessing both high catalytic activity and ionic conductivity.In this study,La_(0.9)Ba_(0.1)Co_(0.7)Ni_(0.3)O_(3−δ)(LBCN9173)and La_(0.9)Ba_(0.1)Co_(0.7)Ni_(0.3)O_(3−δ)(LCCN9173)oxides are tailored as promising anodes by machine learning model,achieving the synergistic enhancement of water oxidation reaction kinetics and proton conduction,which is confirmed by comprehensively analyzing experiment and density functional theory calculation results.Furthermore,the anodic reaction mechanisms for P-SOECs with these anodes are elucidated by analyzing distribution of relaxation time spectra and Gibbs energy of water oxidation reaction,manifesting that the dissociation of H_(2)O is facilitated on LBCN9173 anode.As a result,P-SOEC with LBCN9173 anode demonstrates a top-rank current density of 2.45 A cm^(−2)at 1.3 V and an extremely low polarization resistance of 0.05Ωcm^(2)at 650°C.This multi-scale,multi-faceted research approach not only discovered a high-performance anode but also proved the robust framework for the machine learning-assisted design of anodes for P-SOECs.展开更多
The synthesis of Ta-substituted polyoxometalates has always been an attractive but challenging goal.Three novel tantalum-containing 12-tungsto-2-phosphates were successfully prepared using the water bath method.The mo...The synthesis of Ta-substituted polyoxometalates has always been an attractive but challenging goal.Three novel tantalum-containing 12-tungsto-2-phosphates were successfully prepared using the water bath method.The monomer,K_(11)Li[P_(2)W_(12)(TaO_(2))_(6)O_(56)]·19H_(2)O(1),is composed of{P_(2)W_(12)}and 6{Ta(O_(2))}building blocks,similar to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-).Monomer 1 polymerized to form two cis-trans dimers,K1_(3)Li_(6)H-cis-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·61H_(2)O(2)and KNa_(3)Li_(4)H_(12)-trans-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·37H_(2)O(3).Compounds 1-3 can serve as a structural motif to manufacture additional fascinating molecular clusters,promoting the advancement of POM chemistry.In contrast to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-),compound 1 exhibits exceptional stability,evidenced by ESI-MS,IR,and NMR spectroscopy.In addition,2 and 3 exhibit high proton conductivity and superior water adsorption properties.展开更多
Peroxide ligation of aqueous metal-oxo clusters provides rich speciation and structural diversity.Here,three novel transition-metal derivatives of polyoxometalate anions,[Ni_(2)(H_(2)O)_(10){P_(4)Ta_(6)(O_(2))_(6)O_(2...Peroxide ligation of aqueous metal-oxo clusters provides rich speciation and structural diversity.Here,three novel transition-metal derivatives of polyoxometalate anions,[Ni_(2)(H_(2)O)_(10){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(6-)(1a),[Zn(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(2a)and[Cd(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(3a),have been successfully synthesized by adopting a one-pot reaction strategy.All of these hexatantalates are built from a new-type phosphorus-incorporated hexatantalates.We investigated the solution behaviors,and the peak assignments of the MS spectra indicated some degree of stability of them in water.Furthermore,the proton-conducting ability of compound 1a was also explored and it has shown well conductivity at high relative humidities,with conductivity achieved 1.22×10^(-3) S/cm(85℃,90%RH).展开更多
Protonic ceramic electrolysis cells(PCECs),which permit high-temperature electrolysis of water,exhibit various advantages over conventional solid oxide electrolysis cells(SOECs),including cost-effectiveness and the po...Protonic ceramic electrolysis cells(PCECs),which permit high-temperature electrolysis of water,exhibit various advantages over conventional solid oxide electrolysis cells(SOECs),including cost-effectiveness and the potential to operate at low-/intermediate-temperature ranges with high performance and efficiency.Although many efforts have been made in recent years to improve the electrochemical characteristics of PCECs,certain challenges involved in scaling them up remain unresolved.In the present work,we present a twin approach of combining the tape-calendering method with all-Ni-based functional electrodes with the aim of fabricating a tubular-designed PCEC having an enlarged electrode area(4.6 cm^2).This cell,based on a 25μm-thick BaCe0.5Zr0.3Dy0.2O3-δ proton-conducting electrolyte,a nickelbased cermet and a Pr1.95Ba0.05NiO4+δ oxygen electrode,demonstrates a high hydrogen production rate(19 m L min^-1 at 600℃),which surpasses the majority of results reported for traditional button-or planar-type PCECs.These findings increase the scope for scaling up solid oxide electrochemical cells and maintaining their operability at reducing temperatures.展开更多
The co-firing stage is an unavoidable step in the fabrication process of solid oxide fuel cells(SOFCs),and avoiding unwanted interfacial reactions is crucial for cathode construction during the co-firing process.In th...The co-firing stage is an unavoidable step in the fabrication process of solid oxide fuel cells(SOFCs),and avoiding unwanted interfacial reactions is crucial for cathode construction during the co-firing process.In this study,LiMn_(2)O_(4)(LiMO),a traditional electrode material for Li-ion batteries,was discovered to have protonation and proton diffusion properties,showing significant promise as a cathode for proton-conducting SOFCs(H-SOFCs).However,obvious interactions between the LiMO cathode and BaCe_(0.7)Zr_(0.1)Y_(0.2)O_(3−δ)(BCZY)electrolyte can be identified during the co-firing process using the conventional sintering method,resulting in poor performance and making the use of LiMO in H-SOFCs challenging.To address this issue,the Joule heating process is used to produce the LiMO cathode for H-SOFCs.In contrast to the traditional co-firing process,which takes a few hours,the Joule heating method,which completes the co-sintering procedure in a few seconds,can successfully bind the LiMO to the BCZY electrolyte with no visible interlayer reactions or elemental diffusions.As a result,the full potential of LiMO for H-SOFCs is realized,resulting in a high fuel cell output of 1426 mW·cm^(−2)at 700℃,approximately double that of the cell utilizing the normally sintered LiMO cathode.To the best of our knowledge,this is the first study to use Joule heating to prevent the cathode/electrolyte interfacial reaction in H-SOFCs,which presents an interesting approach for manufacturing and may also breathe new life into some materials that are previously incompatible with H-SOFCs.展开更多
A high-entropy ceramic oxide is used as the cathode for the first time for proton-conducting solid oxide fuel cells(H-SOFCs).The Fe_(0.6)Mn_(0.6)Co_(0.6)Ni_(0.6)Cr_(0.6)O_(4)(FMCNC)high-entropy spinel oxide has been s...A high-entropy ceramic oxide is used as the cathode for the first time for proton-conducting solid oxide fuel cells(H-SOFCs).The Fe_(0.6)Mn_(0.6)Co_(0.6)Ni_(0.6)Cr_(0.6)O_(4)(FMCNC)high-entropy spinel oxide has been successfully prepared,and the in situ chemical stability test demonstrates that the FMCNC material has good stability against CO_(2).The first-principles calculation indicates that the high-entropy structure enhances the properties of the FMCNC material that surpasses their individual components,leading to lower O_(2)adsorption energy for FMCNC than that for the individual components.The HSOFC using the FMCNC cathode reaches an encouraging peak power density(PPD)of 1052 mW·cm^(-2)at 700℃,which is higher than those of the H-SOFCs reported recently.Additional comparison was made between the high-entropy FMCNC cathode and the traditional Mn_(1.6)Cu_(1.4)O_(4)(MCO)spinel cathode without the high-entropy structure,revealing that the formation of the high-entropy material allows the enhanced protonation ability as well as the movement of the O p-band center closer to the Fermi level,thus improving the cathode catalytic activity.As a result,the high-entropy FMCNC has a much-decreased polarization resistance of 0.057Ω·cm^(2)at 700℃,which is half of that for the traditional MCO spinel cathode without the high-entropy design.The excellent performance of the FMCNC cell indicates that the high-entropy design makes a new life for the spinel oxide as the cathode for HSOFCs,offering a novel and promising route for the development of high-performance materials for H-SOFCs.展开更多
Sr-doped LaMnO_(3)(LSM)which is the firstgeneration cathode for solid oxide fuel cells(SOFC;)has been tailored with Zn ions,aiming to achieve improved protonation ability for proton-conducting SOFCs(H-SOFCs).The new S...Sr-doped LaMnO_(3)(LSM)which is the firstgeneration cathode for solid oxide fuel cells(SOFC;)has been tailored with Zn ions,aiming to achieve improved protonation ability for proton-conducting SOFCs(H-SOFCs).The new Sr and Zn co-doped LaMnO_(3)(LSMZ)can be successfully synthesized.The first-principle studies indicate that the LSMZ improves the protonation of LSM and decreases the barriers for oxygen vacancy formation,leading to high performance of the LSMZ cathode-based cells.The proposed LSMZ cell shows the highest fuel cell performance among ever reported LSMbased H-SOFCs.In addition,the superior fuel cell performance does not impair its stability.LSMZ is stable against CO_(2),as demonstrated by both in-situ CO_(2)corrosion tests and the first-principles calculations,leading to good long-term stability of the cell.The Zn-doping strategy for the traditional LSM cathode with high performance and good stability brings back the LSM cathode to intermediate temperatures and paves a new way for the research on the LSM-based materials as cathodes for SOFCs.展开更多
Sc-doped Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(SFMSc)was successfully synthesized by partially substituting Mo in Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(SFM)with Sc,resulting in a higher proton diffusion rate in the resultant SFMSc ...Sc-doped Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(SFMSc)was successfully synthesized by partially substituting Mo in Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(SFM)with Sc,resulting in a higher proton diffusion rate in the resultant SFMSc sample.Theoretical calculations showed that doping Sc into SFM lowered the oxygen vacancy formation energy,reduced the energy barrier for proton migration in the oxide,and increased the catalytic activity for oxygen reduction reaction.Next,a proton-conducting solid oxide fuel cell(H-SOFC)with a single-phase SFMSc cathode demonstrated significantly higher cell performance than that of cell based on an Sc-free SFM cathode,achieving 1258 mW cm^(−2)at 700℃.The performance also outperformed that of many other H-SOFCs based on single-phase cobalt-free cathodes.Furthermore,no trade-off between fuel cell performance and material stability was observed.The SFMSc material demonstrated good stability in both the CO_(2)-containing atmosphere and the fuel cell application.The combination of high performance and outstanding stability suggests that SFMSc is an excellent cathode material for H-SOFCs.展开更多
The development of proton,oxygen-ion,and electron mixed conducting materials,known as triple-conduction materials,as cathodes for proton-conducting solid oxide fuel cells(H-SOFCs)is highly desired because they can inc...The development of proton,oxygen-ion,and electron mixed conducting materials,known as triple-conduction materials,as cathodes for proton-conducting solid oxide fuel cells(H-SOFCs)is highly desired because they can increase fuel cell performance by extending the reaction active area.Although oxygen-ion and electron conductions can be measured directly,proton conduction in these oxides is usually estimated indirectly.Because of the instability of cathode materials in a reducing environment,direct measurement of proton conduction in cathode oxide is difficult.The La0.8Sr0.2Sc0.5Fe0.5O3–δ(LSSF)cathode material is proposed for H-SOFCs in this study,which can survive in an H_(2)-containing atmosphere,allowing measurement of proton conduction in LSSF by hydrogen permeation technology.Furthermore,LSSF is discovered to be a unique proton and electron mixed-conductive material with limited oxygen diffusion capability that is specifically designed for H-SOFCs.The LSSF is an appealing cathode choice for H-SOFCs due to its outstanding CO_(2)tolerance and matched thermal expansion coefficient,producing a record-high performance of 2032 mW cm^(−2)at 700℃and good long-term stability under operational conditions.The current study reveals that a new type of proton–electron mixed conducting cathode can provide promising performance for H-SOFCs,opening the way for developing high-performance cathodes.展开更多
Slow oxygen reduction reaction(ORR)involving proton transport remains the limiting factor for electrochemical performance of proton-conducting cathodes.To further reduce the operating temperature of protonic ceramic f...Slow oxygen reduction reaction(ORR)involving proton transport remains the limiting factor for electrochemical performance of proton-conducting cathodes.To further reduce the operating temperature of protonic ceramic fuel cells(PCFCs),developing triple-conducting cathodes with excellent electrochemical performance is required.In this study,K-doped BaCo_(0.4)Fe_(0.4)Zr_(0.2)O_(3−δ)(BCFZ442)series were developed and used as the cathodes of the PCFCs,and their crystal structure,conductivity,hydration capability,and electrochemical performance were characterized in detail.Among them,Ba_(0.9)K_(0.1)Co_(0.4)Fe_(0.4)Zr_(0.2)O_(3−δ)(K10)cathode has the best electrochemical performance,which can be attributed to its high electron(e^(−))/oxygen ion(O^(2−))/H^(+)conductivity and proton uptake capacity.At 750℃,the polarization resistance of the K10 cathode is only 0.009Ω·cm^(2),the peak power density(PPD)of the single cell with the K10 cathode is close to 1 W·cm^(−2),and there is no significant degradation within 150 h.Excellent electrochemical performance and durability make K10 a promising cathode material for the PCFCs.This work can provide a guidance for further improving the proton transport capability of the triple-conducting oxides,which is of great significance for developing the PCFC cathodes with excellent electrochemical performance.展开更多
Two novel anionic single-walled metal-organic nanotubes(MONTs),[(CH_(3))_(2)NH_(2)][ln(cdc)(thb)].2DMF.9.5H_(2)O(FJU-105)and[(CH_(3))_(2)NH_(2)][ln(cdc)(H-btc)]-2DMA·11H_(2)O(FJU-106)(H_(2)cdc=9H-carbazole-3,6-di...Two novel anionic single-walled metal-organic nanotubes(MONTs),[(CH_(3))_(2)NH_(2)][ln(cdc)(thb)].2DMF.9.5H_(2)O(FJU-105)and[(CH_(3))_(2)NH_(2)][ln(cdc)(H-btc)]-2DMA·11H_(2)O(FJU-106)(H_(2)cdc=9H-carbazole-3,6-dicarboxylic acid,H_(2)thb=2,5-thiophene dicarboxylic acid,H3btc=1,3,5-benzene tricarboxylic acid),are achieved by employing[ln_(6)(cdc)_(6)]^(6+)metalloring cluster with largest diameter as the secondary building blocks(SBUs).The inner surface of FJU-106 is functionalized by uncoordinated-COOH groups of the H-btc linkers,leading to a higher proton conduction than FJU-105.At 70℃,FJU-106 displays the proton conduction performances among MONTs,up to 1.80×10^(-2)S·cm(^-1).And FJU-105 and FJU-106 are the first examples of MONT proton conductors operating at subzero temperature.展开更多
While double perovskites of PrBaCo_(2)O_(6)(PBC)have been extensively developed as the cathodes for proton-conducting solid oxide fuel cells(H-SOFCs),the effects of Sr-or Ca-doping at the A site on the activity and st...While double perovskites of PrBaCo_(2)O_(6)(PBC)have been extensively developed as the cathodes for proton-conducting solid oxide fuel cells(H-SOFCs),the effects of Sr-or Ca-doping at the A site on the activity and stability of the oxygen reduction reaction are yet to be fully studied.Here,the effect of A-site doping on the oxygen reduction reaction activity and stability has been studied by evaluating the performance of both symmetrical and single cells.It is shown that Ca-doped PBC(PrBa_(0.8)Ca_(0.2)Co_(2)O_(6),PBCC)shows a slightly smaller polarization resistance(0.076Ωcm^(2))than that(0.085Ωcm^(2))of Sr-doped PBC(PrBa0.8Sr0.2Co2O6,PBSC)at 700◦C in wet air.Moreover,the degradation rate of PBCC is 0.0003Ωcm^(2)h^(−1)(0.3%h−1)in 100 h,about 1/10 of that of PBSC at 700◦C in wet air.In addition,it is also confirmed that single cells with PBCC cathode show higher peak power density(1.22Wcm^(−2)vs.1.08Wcm^(−2)at 650◦C)and better durability(degradation rate of 0.1%h^(−1)vs.0.13%h^(−1))than those with PBSC cathode.The distribution of relaxation time analyses suggests that the better stability of the PBCC electrode may come from the fast and stable surface oxygen exchange process in the medium frequency range of the electrochemical impedance spectrum.展开更多
基金supported by the Natural Sciences and Engineering Research Council(NSERC)of Canada,Discovery Grant(GRPIN-2016-05494)Strategic Research Projects of Alberta Innovates Technology Futures(#G2016000655)funding from the Canada First Research Excellence Fund(CFREF-2015-00001).
文摘“Three-in-one”cathode,achieved via B-site heavy-doping of transition elements(typically Co,Fe)into proton-conductive perovskite,holds promise for enhancing the performance of proton-conducting solid oxide fuel cell(H-SOFC)operated below 650℃for electricity generation.However,its electrochemical behavior above 650℃,essential for improving the efficiency of H-SOFC for fuel conversion,remains insufficiently explored.It is still challenging to propose guidance for the design of“threein-one”cathode toward optimal H-SOFC performance below and above 650℃,with the prerequisite of gaining a comprehensive understanding of the roles of Co and Fe in determining the H-SOFC performance.This work is to address this challenge.Through theoretical/experimental studies,Co is identified to play a role in improving the oxygen reduction reaction(ORR)activity while Fe plays a role in facilitating the cathode/electrolyte interfacial proton conduction.Therefore,if the operating temperature is above 650℃,lowering the Co/Fe ratio in“three-in-one”cathode becomes crucial since the limiting factor shifts from ORR activity to proton conduction.Implementing this strategy,the SOFC using BaCo_(0.15)-Fe_(0.55)Zr_(0.1)Y_(0.1)Yb_(0.1)O_(3−δ)cathode achieves peak power densities of 1.67Wcm^(−2)under H-SOFC mode at 700℃and 2.32Wcm^(−2)under dual ion-conducting SOFC mode at 750℃,which are the highest reported values so far.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning and the Ministry of Trade,Industry and Energy of the Republic of Korea(No.20213030030150)by the National Research Foundation of Korea funded by the Korea government(MSIT)(No.RS-2021-NR057434).
文摘In this work,we present an innovative method for fabricating high-performance proton-conductive fuel cells(PCFCs)by combining magnetron sputtering and flashlight sintering(FLS)techniques.BaZr_(0.8)Y_(0.2)O_(3–δ)(BZY20)electrolyte thin-films are successfully prepared by improving the crystallinity while maintaining the stoichiometry.All components of PCFC,Ni-YSZ anode,BZY20 electrolyte and Pt-GDC cathode are fabricated by sequentially sputtering them onto an AAO substrate.Electrolytic sintering is performed at 550 and 650 V conditions using FLS,effectively solving the Ba evaporation problem encountered in conventional thermal sintering methods.XRD analysis confirms that the perovskite structure is retained,and crystallinity is improved in the FLS samples.Furthermore,FE-SEM and EDS analyses confirm the uniform elemental distribution and consistent thickness of the FLS-treated electrolyte.An optimized PCFC unit cell with FLS-treated electrolyte exhibits a peak power density of 200.0 mW cm^(-2) at 500℃ and an ohmic resistance of 376.0 mΩ cm^(-2).These results suggest that the combination of magnetron sputtering and FLS techniques is a promising approach for fabricating highperformance thin-film PCFCs.
基金financially supported by the National Natural Science Foundation of China(Nos.52072134,52272205)Hubei Province(Nos.2021BCA149,2021CFA072,2022BAA087)the special fund for Science and Technology Innovation Teams of Shanxi Province(No.202304051001007)。
文摘Ethylene(C_(2)H_(4))is a core raw material for the petrochemical industry.It is of economic and environmental significance to use C_(2)H_(6)as the fuel and proton-conducting solid oxide fuel cells(P-SOFC)as the reactor to co-generate electricity and C_(2)H_(4).However,the large-sized Ni particles in the conventional Nicermet anode directly crack C_(2)H_(6);and oxide materials with a mild capability of breaking C-C bonds are generally limited to electrolyte-supported structures with high ohmic impedance.This research for the first time constructs an anode-supported cell using BZCY as the porous scaffold and impregnated double perovskite(PrBa)_(0.95)(Fe_(0.8)Ni_(0.2))_(1.8)Mo_(0.2)O_(6-δ)(PBFNM0.2)as the anode electrocatalysis.FeNi3 nanoparticles exsolve from PBFNM0.2 in H_(2) and uniformly distribute on the surface of perovskite substrate,acting as an active component for C_(2)H_(6)dehydrogenation and electrochemical performance enhancement.The cell with 30 wt%PBFNM0.2 impregnated anode showing a high power density of 508 and 386mW/cm^(2) with H_(2) and C_(2)H_(6)fuels,respectively;high C_(2)H_(6)conversion of 50.9%,C_(2)H_(4)selectivity of 92.1%,and C_(2)H_(4)yield of 46.9%are achieved at 750℃and 700mA/cm^(2),which outperforms all previously electrolyte-supported cells for co-generated electricity and ethylene.Moreover,the cell demonstrated excellent recoverability throughout three dehydrogenation-regeneration cycles.This work provides a practical way with broad application potential to create a novel anode-supported cell efficiently realizing the co-generation of electricity and C_(2)H_(4)from C_(2)H_(6).
基金financial support from the National Natural Science Foundation of China(Nos.51922003,52274406)the Fundamental Research Funds for the Central Universities,China(No.FRF-BD-23-02)。
文摘To address the challenge of insufficient oxygen vacancies in proton-conducting solid oxide fuel cells(H-SOFC),transition metal elements were doped into the B site of lanthanum ferrite perovskite(ABO3)to enhance its catalytic activity further.The Mo-doped La_(0.6)Sr_(0.4)Fe_(0.9)Ni_(0.1)O_(3-δ)(LSFNMx,x=0.05,0.1)powder was synthesized via the sol−gel method,and its crystal structure,conductivity,defect chemistry,and electrochemical performance as an H-SOFC cathode were investigated.The prepared material exhibited a hexagonal structure with the R-3c space group and demonstrates good chemical stability under simulated working conditions.Mo doping increased the surface concentration of oxygen vacancies,leading to the accelerated oxygen transportation.Consequently,the polarization resistance(Rpol)and activation energy(Ea)are reduced.Specifically,LSFNM0.05 showed the lowest polarization resistance(approximately 0.26Ω·cm^(2))at 700°C.LSFNM0.05 achieved a maximum power density of 484 mW/cm^(2)at this temperature,outperforming those of LSFN(353 mW/cm^(2))and LSFNM0.1(365 mW/cm^(2)).
基金supported by the National Natural Science Foundation of China(No.21401195)the Natural Science Foundation for young scholars of Fujian province(2015J05041)the open foundation of State Key Laboratory of Structural Chemistry(20160020)
文摘A novel Zr-substituted polyoxometalate（POM） H2K3[Na6（H2O）9][Zr3Na3O3（H2O）3-（GeW9O（34））2]·12H2O（1） has been made under hydrothermal conditions. 1 was characterized by infrared spectrum, thermogravimetric analysis, powder X-ray diffraction and single-crystal X-ray diffraction. Crystal data are： H（50）O（95）Na9K3Ge2Zr3W（1）8, hexagonal space group P63/mmc, a = 15.2251（6）, b = 15.2251（6）, c = 25.035（2） , V = 5025.7（6） 3, Z = 2, Dc = 3.716 mg/m3, μ = 21.648 mm（-1）, F（000） = 4726, the final R = 0.0259 and w R = 0.0647 for 1487 observed reflections with I 2σ（I）. Single-crystal X-ray structure analysis reveals that 1 exhibits a 3-dimensional framework structure based on Zr3Na3-substituted polyanions [Zr3Na3O3（H2O）3（GeW9O（34））2]（11-） and [Na6（H2O）9]（6＋） clusters building blocks. UV-Vis spectrum indicates that 1 is a wide-gap semiconductor. In addition, the proton-conducting property of 1 was also investigated.
文摘The liquid citrate method was used to synthesize perovskite-type SrCe0.9 Y0.1O3-α powder. SrCe09Y01O3-α membranes were prepared from the powder by sintering at 1450℃ for 10 h. The reactions in the process of the heat treatment were studied by XRD and DSC/TG. The microstructure of the powder and the membrane was observed by SEM. The results indicate that the perovskite-type SrCe0.9Y0.1 O3-α can be synthesized at 1100℃. The particle size of the synthesized SrCe0.9Y0.1O3-α powder is less than 1μm. The powder can be densified at 1450℃.
基金supported by National Natural Science Foundation of China(No.12301626,No.22409033,and No.22409035)Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110612,No.2022A1515110470 and No.2024A1515011849)+1 种基金Funding by Science and Technology Projects in Guangzhou(No.2025A03J3089 and No.2024A04J4111)Guangdong Engineering Technology Research Center for Hydrogen Energy and Fuel Cells.
文摘In the global trend of vigorously developing hydrogen energy,proton-conducting solid oxide electrolysis cells(P-SOECs)have attracted significant attention due to their advantages of high efficiency and not requiring precious metals.However,the application of P-SOECs faces challenges,particularly in developing high-performance anodes possessing both high catalytic activity and ionic conductivity.In this study,La_(0.9)Ba_(0.1)Co_(0.7)Ni_(0.3)O_(3−δ)(LBCN9173)and La_(0.9)Ba_(0.1)Co_(0.7)Ni_(0.3)O_(3−δ)(LCCN9173)oxides are tailored as promising anodes by machine learning model,achieving the synergistic enhancement of water oxidation reaction kinetics and proton conduction,which is confirmed by comprehensively analyzing experiment and density functional theory calculation results.Furthermore,the anodic reaction mechanisms for P-SOECs with these anodes are elucidated by analyzing distribution of relaxation time spectra and Gibbs energy of water oxidation reaction,manifesting that the dissociation of H_(2)O is facilitated on LBCN9173 anode.As a result,P-SOEC with LBCN9173 anode demonstrates a top-rank current density of 2.45 A cm^(−2)at 1.3 V and an extremely low polarization resistance of 0.05Ωcm^(2)at 650°C.This multi-scale,multi-faceted research approach not only discovered a high-performance anode but also proved the robust framework for the machine learning-assisted design of anodes for P-SOECs.
基金supported by the National Natural Science Foundation of China(Nos.22071044,21771054 and 22171071)。
文摘The synthesis of Ta-substituted polyoxometalates has always been an attractive but challenging goal.Three novel tantalum-containing 12-tungsto-2-phosphates were successfully prepared using the water bath method.The monomer,K_(11)Li[P_(2)W_(12)(TaO_(2))_(6)O_(56)]·19H_(2)O(1),is composed of{P_(2)W_(12)}and 6{Ta(O_(2))}building blocks,similar to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-).Monomer 1 polymerized to form two cis-trans dimers,K1_(3)Li_(6)H-cis-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·61H_(2)O(2)and KNa_(3)Li_(4)H_(12)-trans-[P_(2)W_(12)Ta_(4)(TaO_(2))_(2)O_(59)]_(2)·37H_(2)O(3).Compounds 1-3 can serve as a structural motif to manufacture additional fascinating molecular clusters,promoting the advancement of POM chemistry.In contrast to[P_(2)W_(12)(NbO_(2))_(6)O_(56)]^(12-),compound 1 exhibits exceptional stability,evidenced by ESI-MS,IR,and NMR spectroscopy.In addition,2 and 3 exhibit high proton conductivity and superior water adsorption properties.
基金funded by the National Natural Science Foundation of China(Nos.22171071,22071044,21771054 and 21571050)。
文摘Peroxide ligation of aqueous metal-oxo clusters provides rich speciation and structural diversity.Here,three novel transition-metal derivatives of polyoxometalate anions,[Ni_(2)(H_(2)O)_(10){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(6-)(1a),[Zn(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(2a)and[Cd(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(3a),have been successfully synthesized by adopting a one-pot reaction strategy.All of these hexatantalates are built from a new-type phosphorus-incorporated hexatantalates.We investigated the solution behaviors,and the peak assignments of the MS spectra indicated some degree of stability of them in water.Furthermore,the proton-conducting ability of compound 1a was also explored and it has shown well conductivity at high relative humidities,with conductivity achieved 1.22×10^(-3) S/cm(85℃,90%RH).
基金supported by the Russian Foundation for Basic Research (grant no. 18-38-20063)the Council of the President of the Russian Federation (scholarship no. СП-161.2018.1) for supporting the studies devoted to new MIEC materials
文摘Protonic ceramic electrolysis cells(PCECs),which permit high-temperature electrolysis of water,exhibit various advantages over conventional solid oxide electrolysis cells(SOECs),including cost-effectiveness and the potential to operate at low-/intermediate-temperature ranges with high performance and efficiency.Although many efforts have been made in recent years to improve the electrochemical characteristics of PCECs,certain challenges involved in scaling them up remain unresolved.In the present work,we present a twin approach of combining the tape-calendering method with all-Ni-based functional electrodes with the aim of fabricating a tubular-designed PCEC having an enlarged electrode area(4.6 cm^2).This cell,based on a 25μm-thick BaCe0.5Zr0.3Dy0.2O3-δ proton-conducting electrolyte,a nickelbased cermet and a Pr1.95Ba0.05NiO4+δ oxygen electrode,demonstrates a high hydrogen production rate(19 m L min^-1 at 600℃),which surpasses the majority of results reported for traditional button-or planar-type PCECs.These findings increase the scope for scaling up solid oxide electrochemical cells and maintaining their operability at reducing temperatures.
基金supported by the National Natural Science Foundation of China(No.52272216)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.24KJB430001).
文摘The co-firing stage is an unavoidable step in the fabrication process of solid oxide fuel cells(SOFCs),and avoiding unwanted interfacial reactions is crucial for cathode construction during the co-firing process.In this study,LiMn_(2)O_(4)(LiMO),a traditional electrode material for Li-ion batteries,was discovered to have protonation and proton diffusion properties,showing significant promise as a cathode for proton-conducting SOFCs(H-SOFCs).However,obvious interactions between the LiMO cathode and BaCe_(0.7)Zr_(0.1)Y_(0.2)O_(3−δ)(BCZY)electrolyte can be identified during the co-firing process using the conventional sintering method,resulting in poor performance and making the use of LiMO in H-SOFCs challenging.To address this issue,the Joule heating process is used to produce the LiMO cathode for H-SOFCs.In contrast to the traditional co-firing process,which takes a few hours,the Joule heating method,which completes the co-sintering procedure in a few seconds,can successfully bind the LiMO to the BCZY electrolyte with no visible interlayer reactions or elemental diffusions.As a result,the full potential of LiMO for H-SOFCs is realized,resulting in a high fuel cell output of 1426 mW·cm^(−2)at 700℃,approximately double that of the cell utilizing the normally sintered LiMO cathode.To the best of our knowledge,this is the first study to use Joule heating to prevent the cathode/electrolyte interfacial reaction in H-SOFCs,which presents an interesting approach for manufacturing and may also breathe new life into some materials that are previously incompatible with H-SOFCs.
基金supported by the National Natural Science Foundation of China(Grant No.51972183)Hundred Youth Talents Program of Hunan and the Startup Funding for Talents at University of South China。
文摘A high-entropy ceramic oxide is used as the cathode for the first time for proton-conducting solid oxide fuel cells(H-SOFCs).The Fe_(0.6)Mn_(0.6)Co_(0.6)Ni_(0.6)Cr_(0.6)O_(4)(FMCNC)high-entropy spinel oxide has been successfully prepared,and the in situ chemical stability test demonstrates that the FMCNC material has good stability against CO_(2).The first-principles calculation indicates that the high-entropy structure enhances the properties of the FMCNC material that surpasses their individual components,leading to lower O_(2)adsorption energy for FMCNC than that for the individual components.The HSOFC using the FMCNC cathode reaches an encouraging peak power density(PPD)of 1052 mW·cm^(-2)at 700℃,which is higher than those of the H-SOFCs reported recently.Additional comparison was made between the high-entropy FMCNC cathode and the traditional Mn_(1.6)Cu_(1.4)O_(4)(MCO)spinel cathode without the high-entropy structure,revealing that the formation of the high-entropy material allows the enhanced protonation ability as well as the movement of the O p-band center closer to the Fermi level,thus improving the cathode catalytic activity.As a result,the high-entropy FMCNC has a much-decreased polarization resistance of 0.057Ω·cm^(2)at 700℃,which is half of that for the traditional MCO spinel cathode without the high-entropy design.The excellent performance of the FMCNC cell indicates that the high-entropy design makes a new life for the spinel oxide as the cathode for HSOFCs,offering a novel and promising route for the development of high-performance materials for H-SOFCs.
基金supported by the National Natural Science Foundation of China(51972183 and 51972128)the Startup Funding for Talents at the University of South China。
文摘Sr-doped LaMnO_(3)(LSM)which is the firstgeneration cathode for solid oxide fuel cells(SOFC;)has been tailored with Zn ions,aiming to achieve improved protonation ability for proton-conducting SOFCs(H-SOFCs).The new Sr and Zn co-doped LaMnO_(3)(LSMZ)can be successfully synthesized.The first-principle studies indicate that the LSMZ improves the protonation of LSM and decreases the barriers for oxygen vacancy formation,leading to high performance of the LSMZ cathode-based cells.The proposed LSMZ cell shows the highest fuel cell performance among ever reported LSMbased H-SOFCs.In addition,the superior fuel cell performance does not impair its stability.LSMZ is stable against CO_(2),as demonstrated by both in-situ CO_(2)corrosion tests and the first-principles calculations,leading to good long-term stability of the cell.The Zn-doping strategy for the traditional LSM cathode with high performance and good stability brings back the LSM cathode to intermediate temperatures and paves a new way for the research on the LSM-based materials as cathodes for SOFCs.
基金supported by the National Natural Science Foundation of China(51972183)the Startup Funding for Talents at the University of South China。
文摘Sc-doped Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(SFMSc)was successfully synthesized by partially substituting Mo in Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)(SFM)with Sc,resulting in a higher proton diffusion rate in the resultant SFMSc sample.Theoretical calculations showed that doping Sc into SFM lowered the oxygen vacancy formation energy,reduced the energy barrier for proton migration in the oxide,and increased the catalytic activity for oxygen reduction reaction.Next,a proton-conducting solid oxide fuel cell(H-SOFC)with a single-phase SFMSc cathode demonstrated significantly higher cell performance than that of cell based on an Sc-free SFM cathode,achieving 1258 mW cm^(−2)at 700℃.The performance also outperformed that of many other H-SOFCs based on single-phase cobalt-free cathodes.Furthermore,no trade-off between fuel cell performance and material stability was observed.The SFMSc material demonstrated good stability in both the CO_(2)-containing atmosphere and the fuel cell application.The combination of high performance and outstanding stability suggests that SFMSc is an excellent cathode material for H-SOFCs.
基金National Natural Science Foundation of China,Grant/Award Numbers:52272216,51972183Hundred Youth Talents Program of HunanStartup Funding for Talents at University of South China。
文摘The development of proton,oxygen-ion,and electron mixed conducting materials,known as triple-conduction materials,as cathodes for proton-conducting solid oxide fuel cells(H-SOFCs)is highly desired because they can increase fuel cell performance by extending the reaction active area.Although oxygen-ion and electron conductions can be measured directly,proton conduction in these oxides is usually estimated indirectly.Because of the instability of cathode materials in a reducing environment,direct measurement of proton conduction in cathode oxide is difficult.The La0.8Sr0.2Sc0.5Fe0.5O3–δ(LSSF)cathode material is proposed for H-SOFCs in this study,which can survive in an H_(2)-containing atmosphere,allowing measurement of proton conduction in LSSF by hydrogen permeation technology.Furthermore,LSSF is discovered to be a unique proton and electron mixed-conductive material with limited oxygen diffusion capability that is specifically designed for H-SOFCs.The LSSF is an appealing cathode choice for H-SOFCs due to its outstanding CO_(2)tolerance and matched thermal expansion coefficient,producing a record-high performance of 2032 mW cm^(−2)at 700℃and good long-term stability under operational conditions.The current study reveals that a new type of proton–electron mixed conducting cathode can provide promising performance for H-SOFCs,opening the way for developing high-performance cathodes.
基金the support by the National Key R&D Program of China(2018YFE0124700)the National Natural Science Foundation of China(52102279,52072134,and 51972128)+1 种基金Natural Science Foundation of Shandong Province(ZR2021QE283)Department of Science and Technology of Hubei Province(2021CBA149 and 2021CFA072).
文摘Slow oxygen reduction reaction(ORR)involving proton transport remains the limiting factor for electrochemical performance of proton-conducting cathodes.To further reduce the operating temperature of protonic ceramic fuel cells(PCFCs),developing triple-conducting cathodes with excellent electrochemical performance is required.In this study,K-doped BaCo_(0.4)Fe_(0.4)Zr_(0.2)O_(3−δ)(BCFZ442)series were developed and used as the cathodes of the PCFCs,and their crystal structure,conductivity,hydration capability,and electrochemical performance were characterized in detail.Among them,Ba_(0.9)K_(0.1)Co_(0.4)Fe_(0.4)Zr_(0.2)O_(3−δ)(K10)cathode has the best electrochemical performance,which can be attributed to its high electron(e^(−))/oxygen ion(O^(2−))/H^(+)conductivity and proton uptake capacity.At 750℃,the polarization resistance of the K10 cathode is only 0.009Ω·cm^(2),the peak power density(PPD)of the single cell with the K10 cathode is close to 1 W·cm^(−2),and there is no significant degradation within 150 h.Excellent electrochemical performance and durability make K10 a promising cathode material for the PCFCs.This work can provide a guidance for further improving the proton transport capability of the triple-conducting oxides,which is of great significance for developing the PCFC cathodes with excellent electrochemical performance.
基金the National Natural Science Foundation of China(Nos.21673039,21573042,21805039,21975044,21971038)the Fujian Provincial Department of Science and Technology(Nos.2018J07001,2019H6012)。
文摘Two novel anionic single-walled metal-organic nanotubes(MONTs),[(CH_(3))_(2)NH_(2)][ln(cdc)(thb)].2DMF.9.5H_(2)O(FJU-105)and[(CH_(3))_(2)NH_(2)][ln(cdc)(H-btc)]-2DMA·11H_(2)O(FJU-106)(H_(2)cdc=9H-carbazole-3,6-dicarboxylic acid,H_(2)thb=2,5-thiophene dicarboxylic acid,H3btc=1,3,5-benzene tricarboxylic acid),are achieved by employing[ln_(6)(cdc)_(6)]^(6+)metalloring cluster with largest diameter as the secondary building blocks(SBUs).The inner surface of FJU-106 is functionalized by uncoordinated-COOH groups of the H-btc linkers,leading to a higher proton conduction than FJU-105.At 70℃,FJU-106 displays the proton conduction performances among MONTs,up to 1.80×10^(-2)S·cm(^-1).And FJU-105 and FJU-106 are the first examples of MONT proton conductors operating at subzero temperature.
基金Natural Science Foundation of Guangdong Province,Grant/Award Number:2021A1515010395Fundamental Research Funds for the Central Universities,Grant/Award Number:2022ZYGXZR002+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:22179039,22005105Pearl River Talent Recruitment Program,Grant/Award Number:2019QN01C693Guangdong Innovative and Entrepreneurial Research Team Program,Grant/Award Number:2021ZT09L392。
文摘While double perovskites of PrBaCo_(2)O_(6)(PBC)have been extensively developed as the cathodes for proton-conducting solid oxide fuel cells(H-SOFCs),the effects of Sr-or Ca-doping at the A site on the activity and stability of the oxygen reduction reaction are yet to be fully studied.Here,the effect of A-site doping on the oxygen reduction reaction activity and stability has been studied by evaluating the performance of both symmetrical and single cells.It is shown that Ca-doped PBC(PrBa_(0.8)Ca_(0.2)Co_(2)O_(6),PBCC)shows a slightly smaller polarization resistance(0.076Ωcm^(2))than that(0.085Ωcm^(2))of Sr-doped PBC(PrBa0.8Sr0.2Co2O6,PBSC)at 700◦C in wet air.Moreover,the degradation rate of PBCC is 0.0003Ωcm^(2)h^(−1)(0.3%h−1)in 100 h,about 1/10 of that of PBSC at 700◦C in wet air.In addition,it is also confirmed that single cells with PBCC cathode show higher peak power density(1.22Wcm^(−2)vs.1.08Wcm^(−2)at 650◦C)and better durability(degradation rate of 0.1%h^(−1)vs.0.13%h^(−1))than those with PBSC cathode.The distribution of relaxation time analyses suggests that the better stability of the PBCC electrode may come from the fast and stable surface oxygen exchange process in the medium frequency range of the electrochemical impedance spectrum.
