Ternary Ni–Co–Fe Exsolved Nanoparticles/Perovskite System for Energy Applications: Nanostructure Characterization and Electrochemical Activity

Santaya, Mariano; Troiani, Horacio Esteban; Caneiro, A.; Mogni, L.

doi:10.1021/acsaem.0c01997

Cited by 17 publications

(8 citation statements)

References 25 publications

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“…For samples A5 and B5 reduced at 800 °C, the spectra show that after reduction, the bulk is primarily LaFeO 3 with La 2 O 3 . The reflections at ∼44 and ∼45 2θ are attributed to the presence of NiFeCo alloys, confirming the exsolution of multimetallic nanoparticles. The presence of ∼45 2θ could also indicate Fe 2 O 3 ; however, we believe that it is unlikely.…”

Section: Results and Discussionsupporting

confidence: 52%

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Exsolution of Embedded Ni–Fe–Co Nanoparticles: Implications for Dry Reforming of Methane

Shah

Pan

et al. 2021

ACS Appl. Nano Mater.

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As a promising robust and thermally stable dry methane reforming (DRM) catalyst, perovskite precursors for the controlled nucleation and growth of NiFeCo nanoparticles from La(Fe,Ni,Co)O 3 precursor structures have been explored in this work. We study the structure−reactivity relationship of the formed NiFeCo nanoparticles as a function of the reduction temperature, reaction environment, and bulk point defects. We closely examine different levers that can control the size, composition, and reactivity of NiFeCo nanoparticles. The material properties are investigated by a combination of characterization techniques such as X-ray diffraction, high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM), and energydispersive X-ray spectroscopy. Dry reforming of methane (DRM) reaction testing and temperature-programmed surface reaction (TPSR) experiments are used to probe the catalyst performance and regenerability of the multimetallic nanoparticles. NiFeCo nanoparticles formed from perovskite oxide precursors show a greater propensity to form alloys or aggregates than the conventional wet coimpregnation method. HAADF-STEM and TPSR experiments suggest that the NiFeCo nanoparticles formed are initially Ferich but become Ni-and Co-rich in the reactive atmosphere after aging for 24 h. This works provides insight into relevant factors that can control the properties of multimetallic nanoparticles formed from perovskite oxide precursors.

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Section: Results and Discussionsupporting

confidence: 52%

“…For samples A5 and B5 reduced at 800 °C, the spectra show that after reduction, the bulk is primarily LaFeO 3 with La 2 O 3 . The reflections at ∼44 and ∼45 2θ are attributed to the presence of NiFeCo 35 alloys, S2. Sample A5 has a surface area of 3.5 m 2 /g compared to a surface area of 3.2 m 2 /g for the B5 sample.…”

Section: Resultsmentioning

confidence: 99%

Exsolution of Embedded Ni–Fe–Co Nanoparticles: Implications for Dry Reforming of Methane

Shah

Pan

et al. 2021

ACS Appl. Nano Mater.

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“…The Sr-deciency is meant to stabilize the perovskite structure by compensating for the necessary B-site depletion that occurs during exsolution, intending to prevent excessive Sr segregation. 21,31 However, a characterization of the surface chemistry and oxidation states of the transition metals at the solid/gas interface during operation that could provide a mechanistic description of the interplay between exsolution and surface Sr enrichment or limiting steps of the solid/gas reaction is still lacking. Moreover, it is not known whether exsolution in STFN is sufficiently reversible to enable a material regeneration by reoxidation.…”

Section: Introductionmentioning

confidence: 99%

Tracking the nanoparticle exsolution/reoxidation processes of Ni-doped SrTi_0.3Fe_0.7O_3−δ electrodes for intermediate temperature symmetric solid oxide fuel cells

et al. 2022

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“…Anyhow, their results indicated an enhanced catalytic activity of the ternary alloy with respect to the binary alloys and single exsolved metallic nanoparticles, illustrating the benefits of multicomponent alloy nanoparticles. In this regard and to the best of our knowledge, the only report of direct Co–Ni–Fe exsolution is the work of Mogni and co-authors using Sr 0.93 (Ti 0.3 Fe 0.56 Ni 0.07 Co 0.07 )O 3−δ as a parent perovskite. However, despite the promise, there is still little understanding about the range of compositional variability of the ternary alloys and how, by adjusting the exsolution conditions, it might change.…”

Section: Introductionmentioning

confidence: 99%

Tuning Ternary Alloyed Nanoparticle Composition and Morphology by Exsolution in Double Perovskite Electrodes for CO₂ Electrolysis

López-García

Almar

Escolástico

et al. 2022

ACS Appl. Energy Mater.

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The intermittent nature of renewable energy resources makes imperative the development of efficient energy storage technologies. Solid oxide electrolysis cells (SOECs) are a promising alternative to energy conversion devices. SOECs can play an important role in the control of greenhouse gases by improving processes such as CO2 electrolysis. In order to enhance SOEC performance, exsolution of metal nanoparticles is emerging for the catalytic surface functionalization of electrodes, preventing sintering issues related to classical impregnation methods and enabling tailoring specific catalytic functions. In this work, a medium-entropy, double perovskite system Sr x FeCo0.2Ni0.2Mn0.1Mo0.5O6−δ (x = 2.0, 1.9, and 1.8) was studied. We provide evidence of Fe–Co–Ni ternary alloyed exsolved nanoparticles, revealing that the alloy composition can be tuned by adjusting the reducing conditions. Exsolution temperature is critical for Fe content in nanoparticles, increasing as temperature increases, but Ni and Co are not significantly affected. Temperature adjustments allowed control over nanoparticle size and population, shrinking and growing, respectively, as temperature decreases. In contrast to what is usually described, A-site deficiency resulted in a decrease in nanoparticle exsolution because of NiO phase formation in x = 1.9 and 1.8, so that the x = 2.0 compound outperformed both non-stoichiometric materials, showing significantly larger populations. The three compounds exhibit important conductivity under both oxidizing and reducing atmospheres, which makes them promising electrodes. The Sr2FeCo0.2Ni0.2Mn0.1Mo0.5O6−δ material was integrated as a cathode in an asymmetrical electrolyte-supported cell, and its electrochemical performance under CO2 electrolysis conditions was studied. Our results showed a boost in electrocatalytic activity upon exsolution at 600 °C when compared to the fuel electrode without exsolved nanoparticles or exsolved at 800 °C, where the appearance of the secondary Ruddlesden-Popper phase was observed. Overall, here, we proved the possibility of obtaining ternary alloy exsolved nanoparticles and tuning their composition to enhance the performance of SOEC devices, paving the path for optimized metal-alloyed exsolved nanoparticle design, which might extend its applicability to other electrocatalytic processes in energy conversion and storage.

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Ternary Ni–Co–Fe Exsolved Nanoparticles/Perovskite System for Energy Applications: Nanostructure Characterization and Electrochemical Activity

Cited by 17 publications

References 25 publications

Exsolution of Embedded Ni–Fe–Co Nanoparticles: Implications for Dry Reforming of Methane

Exsolution of Embedded Ni–Fe–Co Nanoparticles: Implications for Dry Reforming of Methane

Tracking the nanoparticle exsolution/reoxidation processes of Ni-doped SrTi_0.3Fe_0.7O_3−δ electrodes for intermediate temperature symmetric solid oxide fuel cells

Tuning Ternary Alloyed Nanoparticle Composition and Morphology by Exsolution in Double Perovskite Electrodes for CO₂ Electrolysis

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Ternary Ni–Co–Fe Exsolved Nanoparticles/Perovskite System for Energy Applications: Nanostructure Characterization and Electrochemical Activity

Cited by 17 publications

References 25 publications

Exsolution of Embedded Ni–Fe–Co Nanoparticles: Implications for Dry Reforming of Methane

Exsolution of Embedded Ni–Fe–Co Nanoparticles: Implications for Dry Reforming of Methane

Tracking the nanoparticle exsolution/reoxidation processes of Ni-doped SrTi0.3Fe0.7O3−δ electrodes for intermediate temperature symmetric solid oxide fuel cells

Tuning Ternary Alloyed Nanoparticle Composition and Morphology by Exsolution in Double Perovskite Electrodes for CO2 Electrolysis

Contact Info

Product

Resources

About

Tracking the nanoparticle exsolution/reoxidation processes of Ni-doped SrTi_0.3Fe_0.7O_3−δ electrodes for intermediate temperature symmetric solid oxide fuel cells

Tuning Ternary Alloyed Nanoparticle Composition and Morphology by Exsolution in Double Perovskite Electrodes for CO₂ Electrolysis