Surface modification of La(Sr)MnO3 electrodes

Tikhonovich, V.N.; Хартон, В.В.; Naumovich, E.N.; Savitsky, A. A.

doi:10.1016/s0167-2738(97)00505-5

Cited by 50 publications

(16 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is interesting to note that the best performing phase among those studied in the present work contains praseodymium in the A site. There are a number of reports in the literature that consider that the presence of Praseodymium might be responsible for their improved performance as compared to those samples without Pr [41,42]. This is usually ascribed to the possible presence of the redox pair Pr 4+ /Pr 3+ at high temperatures, resulting in the improvement of the electrochemical properties of the cathodes.…”

Section: Overall Discussionmentioning

confidence: 99%

Effect of the A Cation Size Disorder on the Properties of an Iron Perovskite Series for Their Use as Cathodes for SOFCs

et al. 2010

View full text Add to dashboard Cite

In order to develop a cathode that can be used in intermediate temperature solid oxide fuel cells, a family of iron perovskites with the general formula Ln0.5M0.5FeO3–δ (A = Ln1–xMx; Ln = La, Nd and/or Pr; M = Sr, Ca or/and Ba) with fixed divalent dopant concentration x to 0.5, mean A cation radius 〈rA〉 to 1.25 Å but with different A cation size disorder σ2(rA) has been prepared by the conventional solid state reaction. These compounds have been characterised by power X‐ray diffraction (XRD), high‐resolution scanning electron microscopy (SEM), electrical conductivity, I–V measurements and AC impedance spectroscopy. All the samples have a rhombohedral crystal structure (space group: R‐3c). SEM images show that the average grain size increases with increasing σ2(rA) in the bulk samples. The DC four‐probe measurements indicate that electrical conductivity is strongly dependent on the σ2(rA). Electrochemical impedance spectra at 700 and 800 °C revealed that better electrochemical cathode performances are for samples with smaller values of σ2(rA).

show abstract

Section: Overall Discussionmentioning

confidence: 99%

Effect of the A Cation Size Disorder on the Properties of an Iron Perovskite Series for Their Use as Cathodes for SOFCs

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Praseodymium oxide is known to exhibit high catalytic activity in reactions involving oxygen (e.g. [12]). Indeed, this type of doping resulted in moderate increase in oxygen permeation fluxes at temperature below 1223 K (Fig.2A).…”

Section: Surface Limitations Of Oxygen Permeationmentioning

confidence: 99%

“…The present work continues our research of LaGaO 3 -based mixed conductors as potential membrane materials [6][7][8][9][10] and is focused on the studies of oxygen permeability, thermal expansion and stability of La 1-x A x Ga 0.80-y Mg y M 0.20 O 3-δ (A = Sr, Pr; M = Fe, Co, Ni) ceramics. [12] and reference cited); the remaining amounts of Bi 2 O 3 are smaller than the low detection limit of standard analytical techniques. After sintering, the ceramic samples were annealed in air at 1270 K for 3-4 hours and then slowly cooled in order to achieve equilibrium with air at low temperatures.…”

Section: Introductionmentioning

confidence: 96%

Permeabilidad de oxígeno en membranas cerámicas de La(Sr,Pr)Ga(Mg)O<sub>3-Î´</sub> con metales de transición

Yaremchenko¹,

Shaula²,

Хартон³

et al. 2004

Bol. Soc. Esp. Ceram. Vidr.

View full text Add to dashboard Cite

Acceptor-type doping of perovskite-type La 1-x Sr x Ga 0.80-y Mg y M 0.20 O 3-δ (x = 0-0.20, y = 0.15-0.20, M = Fe, Co, Ni) leads to significant enhancement of ionic conductivity and oxygen permeability due to increasing oxygen vacancy concentration. The increase in strontium and magnesium content is accompanied, however, with increasing role of surface exchange kinetics as permeation-limiting factor. At temperatures below 1223 K, the oxygen permeation fluxes through La(Sr)Ga(Mg,M)O 3-δ membranes with thickness less than 1.5 mm are predominantly limited by the exchange rates at membrane surface. The oxygen transport in transition metal-containing La(Sr)Ga(Mg)O 3-δ ceramics increase in the sequence Co < Fe < Ni. The ionic conduction in these phases is, however, lower than that in the parent compounds, La 1-x Sr x Ga 1-y Mg y O 3-δ . The highest level of oxygen permeation, comparable to that of La (Sr) da lugar a una mejora significativa de la conductividad iónica y de la permeabilidad al oxígeno debido al aumento de la concentración de vacantes de oxígeno. Sin embargo, el aumento de la cantidad de estroncio y magnesio viene acompañado de un aumento de la participación de las cinéticas de intercambio superficial como factor limitante de la permeabilidad. A temperaturas por debajo de 1223 K la permeabilidad al flujo de oxígeno a través de las membranas de La(Sr)Ga(Mg,M)O 3-δ con espesor menor de 1.5 mm está limitado principalmente por las velocidades de intercambio en la superficie de la membrana. El transporte de oxígeno en las cerámicas La(Sr)Ga(Mg)O 3-δ que contienen M aumenta en la secuencia Co < Fe < Ni. La conductividad iónica en estas fases es, sin embargo, menor que en la de los compuestos La 1-x Sr x Ga 1-y Mg y O 3-δ . El mayor nivel de permeabilidad de oxígeno, comparable a la de las fases basadas en La(Sr)Fe (

show abstract

“…High performing electrodes based on this family comprise systems like La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSFC) [5,6,7], Sm 0.5 Sr 0.5 CoO 3-δ (SSC) [8], Gd 1-x Sr x CoO 3-δ [9] or Pr 0.8 Sr 0.2 FeO 3-δ (PSF) [10,11]. Lanthanides have a positive effect in the electrochemical activity for oxygen reduction due to their redox couples (like Pr +3 ↔Pr +4 or Sm +3 ↔Sm +2 ) and their controlled basicity.…”

mentioning

confidence: 99%

Improvement of the Electrochemical Performance of Ln_0.58Sr_0.4Fe_0.8Co_0.2O_3 – δ IT‐SOFC Cathodes by Ternary Lanthanide Combinations (La‐Pr‐Sm)

Vert

Serra

2010

Fuel Cells

View full text Add to dashboard Cite

Active perovskite‐based SOFC cathodes have been developed through lanthanide combination in the (La1 – x – yPrxSmy)0.58Sr0.4Fe0.8Co0.2O3 – δ system following a ternary mixture experimental design. These compositions were prepared through a sol–gel method and characterised by electrochemical impedance spectroscopy (EIS) as symmetrical cells on GDC‐electrolyte samples in the 450–650 °C temperature range. The electrochemical properties of the single lanthanide‐based Ln0.58Sr0.4Fe0.8Co0.2O3 – δ compounds were enhanced when different lanthanides were combined together in the same crystalline structure. The observed improvement does not follow a mere additional effect of the performance from the parent Ln0.58Sr0.4Fe0.8Co0.2O3 – δ compounds, i.e. it does not follow a linear behaviour, and the better performance is ascribed to synergetic catalytic effects among lanthanide cations. A reduction in electrode polarisation resistance with respect to non‐substituted compositions is stated for most Ln0.58Sr0.4Fe0.8Co0.2O3 – δ electrode compositions combining two or three lanthanides. Samarium addition to the electrode material involves a substantial reduction in the activation energy and the reduction degree is directly dependant on the samarium amount incorporated in the lattice. The best performing composition comprises a praseodymium‐rich lanthanum‐based electrode material. The experimental data derived from the ternary mixture design were modelled using nonlinear functions and this modelling allowed finding an electrode composition minimising the polarisation resistance while maintaining the activation energy at reduced values. Selected cathode compositions were tested in fully assembled anode‐supported cells and electrochemical characterisation supports the cooperative effect of lanthanide combination.

show abstract

Surface modification of La(Sr)MnO3 electrodes

Cited by 50 publications

References 17 publications

Effect of the A Cation Size Disorder on the Properties of an Iron Perovskite Series for Their Use as Cathodes for SOFCs

Effect of the A Cation Size Disorder on the Properties of an Iron Perovskite Series for Their Use as Cathodes for SOFCs

Permeabilidad de oxígeno en membranas cerámicas de La(Sr,Pr)Ga(Mg)O<sub>3-Î´</sub> con metales de transición

Improvement of the Electrochemical Performance of Ln_0.58Sr_0.4Fe_0.8Co_0.2O_3 – δ IT‐SOFC Cathodes by Ternary Lanthanide Combinations (La‐Pr‐Sm)

Contact Info

Product

Resources

About

Surface modification of La(Sr)MnO3 electrodes

Cited by 50 publications

References 17 publications

Effect of the A Cation Size Disorder on the Properties of an Iron Perovskite Series for Their Use as Cathodes for SOFCs

Effect of the A Cation Size Disorder on the Properties of an Iron Perovskite Series for Their Use as Cathodes for SOFCs

Permeabilidad de oxígeno en membranas cerámicas de La(Sr,Pr)Ga(Mg)O<sub>3-Î´</sub> con metales de transición

Improvement of the Electrochemical Performance of Ln0.58Sr0.4Fe0.8Co0.2O3 – δ IT‐SOFC Cathodes by Ternary Lanthanide Combinations (La‐Pr‐Sm)

Contact Info

Product

Resources

About

Improvement of the Electrochemical Performance of Ln_0.58Sr_0.4Fe_0.8Co_0.2O_3 – δ IT‐SOFC Cathodes by Ternary Lanthanide Combinations (La‐Pr‐Sm)