Optimization and thermal cycling behavior of La2Ce2O7 thermal barrier coatings

Dong, Honggang; Wang, Dongxing; Pei, Yanling; Li, Houyang; Ma, Wen

doi:10.1016/j.ceramint.2012.08.034

Cited by 53 publications

(15 citation statements)

References 31 publications

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“…The pyrochlore Ce 2+ x La 2‐ x O 7‐ δ ( Fd‐3m ) phase is known to act as a mixed oxide and electronic conductor in reducing atmospheres [ 37 ] and can possibly serve as a buffer layer to suppress cation interdiffusion. [ 38,39 ] This renders the phase very attractive for thermochemical CO 2 splitting, so that we proceeded with detailed structural analyses and performance tests. The stoichiometry of each phase of the LSC25M75 composite derived from STEM‐EDS elemental analysis (Table S1, Supporting Information) was used as a starting model for structural refinement.…”

Section: Resultsmentioning

confidence: 99%

“…Pyrochlore oxides (A 2 B 2 O 7 ) are known to be used for a wide range of technological applications, including their utilization as electrolytes in solid oxide fuel cells and as thermal barrier coatings. [ 39,47 ] However, the crystal structure of these materials still remains controversial, and two models based on disordered defect fluorite ( Fm‐3m ) and pyrochlore ( Fd‐3m ) type are mainly considered, depending on the concentration of B‐site cations and the ionic radii ratio of the A and B cations ( r A / r B ). [ 37,48,49 ] The general composition of the identified pyrochlore phase is Ce 1‐ x La x O 2− x /2 (where x = 0.35, 0.40) with La 3+ at the A‐site and Ce 4+ at the B‐site and r(La 3+ )/r(Ce 4+ ) = 1.3, resulting in a large lattice distortion.…”

Section: Resultsmentioning

confidence: 99%

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Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO₂

Naik

Ritter

Bulfin

et al. 2021

Advanced Energy Materials

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Thermochemical splitting of CO2 and H2O via two‐step metal oxide redox cycles offers a promising approach to produce solar fuels. Perovskite‐type oxides with the general formula ABO3 have recently gained attention as an attractive redox material alternative to the state‐of‐the‐art ceria, due to their high structural and thermodynamic tunability. A novel Ce‐substituted lanthanum strontium manganite perovskite‐oxide composite, La3+0.48Sr2+0.52(Ce4+0.06Mn3+0.79)O2.55 (LSC25M75) is introduced, aiming to bridge the gap between ceria and perovskite oxide‐based materials by overcoming their individual thermodynamic constraints. Thermochemical CO2 splitting redox cyclability of LSC25M75 evaluated with a thermogravimetric analyzer and an infrared furnace reactor over 100 consecutive redox cycles demonstrates a twofold higher conversion extent to CO than one of the best Mn‐based perovskite oxides, La0.60Sr0.40MnO3. Based on complementary in situ high temperature neutron, synchrotron X‐ray, and electron diffraction experiments, unprecedented structural and mechanistic insight is obtained into thermochemical perovskite oxide materials. A novel CO2 splitting reaction mechanism is presented, involving reversible temperature induced phase transitions from the n = 1 Ruddlesden–Popper phase (Sr1.10La0.64Ce0.26)MnO3.88 (I4/mmm, K2NiF4‐type) at reduction temperature (1350 °C) to the n = 2 Ruddlesden–Popper phase (Sr2.60La0.22Ce0.18)Mn2O6.6 (I4/mmm, Sr3Ti2O7‐type) at re‐oxidation temperature (1000 °C) after the CO2 splitting step.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO₂

Naik

Ritter

Bulfin

et al. 2021

Advanced Energy Materials

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“…As a molten particle strikes the surface of a solid, it typically spreads out, forming a flat splat and rapidly losing heat to the underlying solid through conduction. A good joining between lamellae is a key for the propagation of segmentation cracks [6][7] . Accordingly, a high heat input to the substrate is one of the most important factors in developing segmentation cracks because high substrate and particle temperature promote the joining of adjacent lamellae.…”

Section: Development Of Segmentation Cracksmentioning

confidence: 99%

Study on formation mechanism of YSZ thermal barrier coatings with segmented structure

Wang¹,

Sun²,

Liu³

et al. 2015

Proceedings of the 5th International Conference on Advanced Design and Manufacturing Engineering

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Abstract. Compared with traditional structures, YSZ TBCs with high segmentation crack density sprayed have exhibited a promising potential in improving TBC thermal shock resistance because the segmentation cracks increase its strain tolerance. A study is presented of formation mechanism of segmented TBC. The segmentation cracks initiate and propagate during the deposition phase, as a result of stress relaxation when the coating is subjected to tensile stress. Also, the crack density reaches a constant value and is not influenced by further plastic deformation of the metal. High heat input to the substrate is the most favorable factor in developing segmentation cracks because particle temperature promote the joining of adjacent lamellae.

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“…[97] Similarly, a La 2 Ce 2 O 7 + YSZ duplex coating has been shown to have better cycling life than a YSZ coating. [156] The use of a duplex coating decreases the temperature of the intermediate YSZ layer for a given operating temperature, which improves the stability of the t¢ phase and thus increases the high temperature limit of the coating system. [157] However, duplex coatings are not always superior to single-layer coatings.…”

Section: Corrosionmentioning

confidence: 99%

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

Fergus

2014

Metallurgical and Materials Transactions E

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One of the important applications of yttria-stabilized zirconia (YSZ) is as a thermal barrier coating for gas turbine engines. While YSZ performs well in this function, the need for increased operating temperatures to achieve higher energy conversion efficiencies, requires the development of improved materials. To meet this challenge, some rare-earth zirconates that form the cubic fluorite-derived pyrochlore structure are being developed for use in thermal barrier coatings due to their low thermal conductivity, excellent chemical stability, and other suitable properties. In this paper, the thermal conductivities of current and prospective oxides for use in thermal barrier coatings are reviewed. The factors affecting the variations and differences in the thermal conductivities and the degradation behaviors of these materials are discussed.

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Optimization and thermal cycling behavior of La2Ce2O7 thermal barrier coatings

Cited by 53 publications

References 31 publications

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO₂

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO₂

Study on formation mechanism of YSZ thermal barrier coatings with segmented structure

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

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Optimization and thermal cycling behavior of La2Ce2O7 thermal barrier coatings

Cited by 53 publications

References 31 publications

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO2

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO2

Study on formation mechanism of YSZ thermal barrier coatings with segmented structure

Zirconia and Pyrochlore Oxides for Thermal Barrier Coatings in Gas Turbine Engines

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Product

Resources

About

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO₂

Reversible Phase Transformations in Novel Ce‐Substituted Perovskite Oxide Composites for Solar Thermochemical Redox Splitting of CO₂