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Luong J, Wang X, Tsung A, Humphrey N, Guo H, Lam BX, Mallikarjun Sharada S, Bowman WJ. Nanoscale Iron Redistribution during Thermochemical Decomposition of CaTi 1-x Fe x O 3-δ Alters the Electrical Transport Pathway: Implications for Oxygen-Transport Membranes, Electrocatalysis, and Photocatalysis. ACS APPLIED NANO MATERIALS 2023; 6:1620-1630. [PMID: 36818540 PMCID: PMC9926871 DOI: 10.1021/acsanm.2c04537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
Potential applications of the earth-abundant, low-cost, and non-critical perovskite CaTi1-x Fe x O3-δ in electrocatalysis, photocatalysis, and oxygen-transport membranes have motivated research to tune its chemical composition and morphology. However, investigations on the decomposition mechanism(s) of CaTi1-x Fe x O3-δ under thermochemically reducing conditions are limited, and direct evidence of the nano- and atomic-level decomposition process is not available in the literature. In this work, the phase evolution of CaTi1-x Fe x O3-δ (x = 0-0.4) was investigated in a H2-containing atmosphere after heat treatments up to 600 °C. The results show that CaTi1-x Fe x O3-δ maintained a stable perovskite phase at low Fe contents while exhibiting a phase decomposition to Fe/Fe oxide nanoparticles as the Fe content increases. In CaTi0.7Fe0.3O3-δ and CaTi0.6Fe0.4O3-δ, the phase evolution to Fe/Fe oxide was greatly influenced by the temperature: Only temperatures of 300 °C and greater facilitated phase evolution. Fully coherent Fe-rich and Fe-depleted perovskite nanodomains were observed directly by atomic-resolution scanning transmission electron microscopy. Prior evidence for such nanodomain formation was not found, and it is thought to result from a near-surface Kirkendall-like phenomenon caused by Fe migration in the absence of Ca and Ti co-migration. Density functional theory simulations of Fe-doped bulk models reveal that Fe in an octahedral interstitial site is energetically more favorable than in a tetrahedral site. In addition to coherent nanodomains, agglomerated Fe/Fe oxide nanoparticles formed on the ceramic surface during decomposition, which altered the electrical transport mechanism. From temperature-dependent electrical conductivity measurements, it was found that heat treatment and phase decomposition change the transport mechanism from thermally activated p-type electronic conductivity through the perovskite to electronic conduction through the iron oxide formed by thermochemical decomposition. This understanding will be useful to those who are developing or employing this and similar earth-abundant functional perovskites for use under reducing conditions, at elevated temperatures, and when designing materials syntheses and processes.
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Affiliation(s)
- Jason Luong
- Department
of Materials Science and Engineering, University
of California, Irvine, Irvine, California92697, United States
| | - Xin Wang
- Department
of Materials Science and Engineering, University
of California, Irvine, Irvine, California92697, United States
| | - Alicia Tsung
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California90089, United States
| | - Nicholas Humphrey
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California90089, United States
| | - Huiming Guo
- Department
of Materials Science and Engineering, University
of California, Irvine, Irvine, California92697, United States
| | - Benjamin X. Lam
- Department
of Materials Science and Engineering, University
of California, Irvine, Irvine, California92697, United States
| | - Shaama Mallikarjun Sharada
- Mork
Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California90089, United States
- Department
of Chemistry, University of Southern California, Los Angeles, California90089, United States
| | - William J. Bowman
- Department
of Materials Science and Engineering, University
of California, Irvine, Irvine, California92697, United States
- Irvine
Materials Research Institute, University
of California, Irvine, Irvine, California92697, United States
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Hell J, Vespa P, Cabodi I, Citti O, Fournet-Fayard F, Fouletier J, Steil M. Blistering phenomenon of molten glass in contact with zirconia-based refractories. Ann Ital Chir 2021. [DOI: 10.1016/j.jeurceramsoc.2021.03.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Poffe E, Kaper H, Ehrhardt B, Gigli L, Aubert D, Nodari L, Gross S, Mascotto S. Understanding Oxygen Release from Nanoporous Perovskite Oxides and Its Effect on the Catalytic Oxidation of CH 4 and CO. ACS APPLIED MATERIALS & INTERFACES 2021; 13:25483-25492. [PMID: 34006105 DOI: 10.1021/acsami.1c02281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The design of nanoporous perovskite oxides is considered an efficient strategy to develop performing, sustainable catalysts for the conversion of methane. The dependency of nanoporosity on the oxygen defect chemistry and the catalytic activity of perovskite oxides toward CH4 and CO oxidation was studied here. A novel colloidal synthesis route for nanoporous, high-temperature stable SrTi0.65Fe0.35O3-δ with specific surface areas (SSA) ranging from 45 to 80 m2/g and pore sizes from 10 to 100 nm was developed. High-temperature investigations by in situ synchrotron X-ray diffraction (XRD) and TG-MS combined with H2-TPR and Mössbauer spectroscopy showed that the porosity improved the release of surface oxygen and the oxygen diffusion, whereas the release of lattice oxygen depended more on the state of the iron species and strain effects in the materials. Regarding catalysis, light-off tests showed that low-temperature CO oxidation significantly benefitted from the enhancement of the SSA, whereas high-temperature CH4 oxidation is influenced more by the dioxygen release. During isothermal long-term catalysis tests, however, the continuous oxygen release from large SSA materials promoted both CO and CH4 conversion. Hence, if SSA maximization turned out to efficiently improve low-temperature and long-term catalysis applications, the role of both reducible metal center concentration and crystal structure cannot be completely ignored, as they also contribute to the perovskite oxygen release properties.
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Affiliation(s)
- Elisa Poffe
- Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz, 6, 20146 Hamburg, Germany
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, Italy
| | - Helena Kaper
- Ceramic Synthesis and Functionalization Laboratory, CNRS/Saint-Gobain CREE, Saint-Gobain Research Provence, 550, Ave Alphonse Jauffret, 84306 Cavaillon, France
| | - Benedikt Ehrhardt
- Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz, 6, 20146 Hamburg, Germany
| | - Lara Gigli
- Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14, 34149 Basovizza, Trieste, Italy
| | - Daniel Aubert
- Ceramic Synthesis and Functionalization Laboratory, CNRS/Saint-Gobain CREE, Saint-Gobain Research Provence, 550, Ave Alphonse Jauffret, 84306 Cavaillon, France
| | - Luca Nodari
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, Italy
- Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia, ICMATE-CNR, C.so Stati Uniti 4, 35127 Padova, Italy
| | - Silvia Gross
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, via Marzolo 1, 35131 Padova, Italy
- Centro Levi Cases, Università degli Studi di Padova, via Marzolo 9, 35131 Padova, Italy
| | - Simone Mascotto
- Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz, 6, 20146 Hamburg, Germany
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Salles C, Steil MC, Fouletier J, Duttine M, Wattiaux A, Marinha D. Long-term stability of iron-doped calcium titanate CaTi0.9Fe0.1O3−δ oxygen transport membranes under non-reactive and reactive atmospheres. J Memb Sci 2019. [DOI: 10.1016/j.memsci.2019.04.049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Répécaud PA, Kaper H, Richard M, Can F, Bion N. Enhancement of Oxygen Activation and Mobility in CaTi
x
Fe1−x
O3−δ
Oxides. ChemCatChem 2017. [DOI: 10.1002/cctc.201700103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Pierre-Alexis Répécaud
- Institut de Chimie des Milieux et Matériaux de Poitiers, IC2MP; University of Poitiers, CNRS, UMR 7285; 4 rue Michel Brunet, TSA 51106 F-86073 Poitiers Cedex 9 France
- Laboratoire de Synthèse et Fonctionnalisation des Céramiques, CNRS/Saint-Gobain, UMR3080; 550 Rue Alphonse Jauffret F-84300 Cavaillon France
| | - Helena Kaper
- Laboratoire de Synthèse et Fonctionnalisation des Céramiques, CNRS/Saint-Gobain, UMR3080; 550 Rue Alphonse Jauffret F-84300 Cavaillon France
| | - Mélissandre Richard
- Institut de Chimie des Milieux et Matériaux de Poitiers, IC2MP; University of Poitiers, CNRS, UMR 7285; 4 rue Michel Brunet, TSA 51106 F-86073 Poitiers Cedex 9 France
| | - Fabien Can
- Institut de Chimie des Milieux et Matériaux de Poitiers, IC2MP; University of Poitiers, CNRS, UMR 7285; 4 rue Michel Brunet, TSA 51106 F-86073 Poitiers Cedex 9 France
| | - Nicolas Bion
- Institut de Chimie des Milieux et Matériaux de Poitiers, IC2MP; University of Poitiers, CNRS, UMR 7285; 4 rue Michel Brunet, TSA 51106 F-86073 Poitiers Cedex 9 France
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