Conductivity of cerium doped BaFeO3−δ and applications for the detection of oxygen

Penwell, William D.; Giorgi, Javier B.

doi:10.1016/j.snb.2013.09.095

Cited by 19 publications

(18 citation statements)

References 30 publications

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“…The results suggest that La and Ce defects are more likely to occupy the Ba over Fe sites. 16,21,25,27 For Y defects, Y Ba exhibits the highest formation energy for A site substitution. This is plausible, given the small ionic radius of the Y cation, relative to Ba 2+ .…”

Section: Substitution Defect Formation Energymentioning

confidence: 99%

“…20,21 Although a recent study demonstrated the successful fabrication of the cubic phase for low temperature (200 o C) upon oxidation in ozone, this structure also exhibited a high oxygen site occupancy. 22 The stabilization of the cubic structure and the high oxygen deficiency has also been obtained by substituting Sr, Ce, La, Y, Ca 16,21,[23][24][25][26][27] into the A-stability, and cell performances comparable to cobalt-based cathodes. 16,21 Although the strategy of stabilizing BFO by substitution is commonly employed, significant ambiguity exists as to the electronic and geometric effects of each site doping.…”

Section: Introductionmentioning

confidence: 99%

“…22 The stabilization of the cubic structure and the high oxygen deficiency has also been obtained by substituting Sr, Ce, La, Y, Ca 16,21,[23][24][25][26][27] into the A-stability, and cell performances comparable to cobalt-based cathodes. 16,21 Although the strategy of stabilizing BFO by substitution is commonly employed, significant ambiguity exists as to the electronic and geometric effects of each site doping. An example is the unclear structural effect of substitution site, this is highlighted in recent studies of 5% doping of Ce Ba 21 and…”

Section: Introductionmentioning

confidence: 99%

“…Most often the substitution location (A site or B site) is determined from the initial stoichiometry of the material constituents and analysis of XRD data. 16,21,24,25,27,[29][30][31][32][33] Stoichiometric expansion with substitution level is also employed to validate the substitution location. 25 35 Moreover, for other Fe-based perovskites (La 0.3 Sr 0.7 FeO 3-δ ), the stoichiometric expansion due to oxygen deficiency was experimentally found to be up to 5% at 900 o C. 36 As doping may also influence the oxygen deficiency in BFO, it is essential to develop a more detailed understanding of the geometric impact of oxygen vacancies.…”

Section: Introductionmentioning

confidence: 99%

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A DFT+U study of A-site and B-site substitution in BaFeO_3−δ

Baiyee

Chen

Ciucci

2015

Phys. Chem. Chem. Phys.

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BaFeO3-δ (BFO)-based perovskites have emerged as cheap and effective oxygen electrocatalysts for oxygen reduction reaction at high temperatures. The BFO cubic phase facilitates a high oxygen deficiency and is commonly stabilised by partial substitution. Understanding the electronic mechanisms of substitution and oxygen deficiency is key to rational material design, and can be realised through DFT analysis. In this work an in-depth first principle DFT+U study is undertaken to determine site distinctive characteristics for 12.5%, Y, La and Ce substitutions in BFO. In particular, it is shown that B-site doped structures exhibit a lower energy cost for oxygen vacancy formation relative to A site doping and pristine BFO. This is attributed to the stabilisation of holes in the oxygen sub-lattice and increased covalency of the Fe-O bonds of the FeO6 octahedra in B-site-substituted BFO. Charge analysis shows that A-site substitution amounts to donor doping and consequently impedes the accommodation of other donors (i.e. oxygen vacancies). However, A-site substitution may also exhibit a higher electronic conductivity due to less lattice distortion for oxygen deficiency compared to B-site doped structures. Furthermore, analysis of the local structural effects provides physical insight into stoichiometric expansions observed for this material.

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Section: Substitution Defect Formation Energymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A DFT+U study of A-site and B-site substitution in BaFeO_3−δ

Baiyee

Chen

Ciucci

2015

Phys. Chem. Chem. Phys.

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“…Platinum mesh was added as a current collector on each side of the combined pellets and electronic conductivity measurements were recorded at temperatures 100-1000°C in air. The methodology and setup diagrams for all the conductivity measurements have been previously reported [33].…”

Section: Conductivity Measurements Of Perovskitesmentioning

confidence: 99%

Promotion of Pt Nanoparticles by Lattice Oxygen in SmFeO3 Perovskite Group for Carbon Monoxide and Ethylene Oxidation

et al. 2015

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The novel Sm 1-x Ce x FeO 3-d (x = 0, 0.01, 0.05) (SCF) perovskites with and without 1 wt% of Pt nanoparticles (NPs) were investigated for carbon monoxide and ethylene oxidation in the temperature range of 25-350°C. All perovskites were predominantly ionic conductors, with ionic conductivities two orders of magnitude higher than the electronic contribution. Furthermore, the cerium doping increases the ionic conductivity of these materials at high temperatures. The bare SCF perovskites possessed catalytic activity for both reactions; however the Pt-supported catalysts had 50-100°C lower light-off temperatures than the corresponding perovskites. More significantly, the enhancement in the catalytic activity of the Pt/SCF family with respect to other Pt-supported catalysts was shown by the lower activation energies, which were 25.7 kJ/mol over Pt/Sm 0.95 Ce 0.05 FeO 3-d and 18.3 kJ/mol over Pt/Sm 0.99 Ce 0.01 FeO 3-d for CO and ethylene oxidation, respectively. The corresponding activation energies for Pt NPs supported on conventional cAl 2 O 3 were 57.1 and 32 kJ/mol, and on ionically conductive yttria-stabilized zirconia (YSZ) were 35.8 and 22 kJ/mol for CO and C 2 H 4 oxidation, respectively. The increased activity was attributed to the high ionic conductivity (O 2-) of the perovskite supports at 100-400°C that facilitates the spontaneous backspillover of O 2-promoters from the lattice to the gas-exposed Pt nanoparticle surface. The promoters alter the adsorption strength of reactants similar to the electrochemical promotion mechanism observed under polarization.

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Structural Engineering of Cobalt‐Free Perovskite Enables Efficient and Durable Oxygen Reduction in Solid Oxide Fuel Cells

Dong

et al. 2022

Small Methods

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Conductivity of cerium doped BaFeO3−δ and applications for the detection of oxygen

Cited by 19 publications

References 30 publications

A DFT+U study of A-site and B-site substitution in BaFeO_3−δ

A DFT+U study of A-site and B-site substitution in BaFeO_3−δ

Promotion of Pt Nanoparticles by Lattice Oxygen in SmFeO3 Perovskite Group for Carbon Monoxide and Ethylene Oxidation

Structural Engineering of Cobalt‐Free Perovskite Enables Efficient and Durable Oxygen Reduction in Solid Oxide Fuel Cells

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Conductivity of cerium doped BaFeO3−δ and applications for the detection of oxygen

Cited by 19 publications

References 30 publications

A DFT+U study of A-site and B-site substitution in BaFeO3−δ

A DFT+U study of A-site and B-site substitution in BaFeO3−δ

Promotion of Pt Nanoparticles by Lattice Oxygen in SmFeO3 Perovskite Group for Carbon Monoxide and Ethylene Oxidation

Structural Engineering of Cobalt‐Free Perovskite Enables Efficient and Durable Oxygen Reduction in Solid Oxide Fuel Cells

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A DFT+U study of A-site and B-site substitution in BaFeO_3−δ

A DFT+U study of A-site and B-site substitution in BaFeO_3−δ