Solid-solid reaction of CuFe2O4 with C in chemical looping system: A comprehensive study

Li, Tianle; Wu, Qiao; Wang, Wenju; Xiao, Yupeng; Liu, Chenlong; Yang, Fufeng

doi:10.1016/j.fuel.2020.117163

Cited by 40 publications

(10 citation statements)

References 54 publications

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“…Furthermore, the FESEM technique was performed to investigate the influence of Ni incorporation in CFO on their morphologies and microstructures, and corresponding FESEM images of the obtained CNFO‐ X ( X = 0, 5, 10, 15, and 20) samples with various cationic compositions are shown in Figure 2A,B and Figure S4. Obviously, the five as‐prepared CNFO‐ X specimens all displayed irregular and interconnected honeycomb‐like morphology regardless of their cationic compositional differences, thus producing a large number of different‐sized pores probably ascribed to the release of numerous gases (such as CO x and N x O y ) during the annealing process of the gel 27 . Specifically, the holes in the mentioned sample gradually increased as the doping amount increased from 0% to 15% (Figure 2A; Figure S4a–c).…”

Section: Resultsmentioning

confidence: 99%

“…Obviously, the five as-prepared CNFO-X specimens all displayed irregular and interconnected honeycomb-like morphology regardless of their cationic compositional differences, thus producing a large number of different-sized pores probably ascribed to the release of numerous gases (such as CO x and N x O y ) during the annealing process of the gel. 27 Specifically, the holes in the mentioned sample gradually increased as the doping amount increased from 0% to 15% (Figure 2A; Figure S4a-c). However, as the doping concentration further rises to 20%, the pore structures in the products begin to fuse leading to a diminution of the pore (Figure S4d).…”

Section: Structural and Physicochemical Analysismentioning

confidence: 95%

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Band gap and oxygen vacancy engineering of honeycomb‐like CuFe₂O₄ spinels toward enhanced high infrared emissivity

et al. 2023

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Recently, copper ferrites have acquired widespread attraction in high infrared radiation fields owing to their remarkable cost efficiency. However, to achieve broader applications under various operating conditions, it is essential to further improve the infrared emissivity, particularly at high temperatures. Herein, the Ni‐doped CuFe2O4 (NCFO) honeycomb‐like frameworks, which are constructed with single‐crystal nano‐subunits, are successfully fabricated via the scalable sol–gel avenue. The unique porous honeycomb framework endows NCFO with enhanced infrared absorption and relieves the stress between coatings and substrates meanwhile. With both band gap and oxygen vacancy (OV) engineering of CuFe2O4 itself via smart Ni doping, a maximum lattice strain, the richest OVs, and the narrowest band gap (∼1.63 eV) are simultaneously achieved for the CuFe2O4 with 15% Ni doping (denoted as CNFO‐15). Benefiting from the synergy of these external and intrinsic contributions, the CNFO‐15 possesses an ultrahigh infrared emissivity (∼0.975) in the wavelength range of 3–5 µm at a test temperature of 800°C. Moreover, the CNFO‐15‐based coating displays superior infrared radiation performance with outstanding high‐temperature resistance. More meaningfully, the constructive design here will provide a distinctive perspective for future large‐scale fabrication of advanced high‐infrared‐emissivity coatings.

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Section: Resultsmentioning

confidence: 99%

Section: Structural and Physicochemical Analysismentioning

confidence: 95%

Band gap and oxygen vacancy engineering of honeycomb‐like CuFe₂O₄ spinels toward enhanced high infrared emissivity

et al. 2023

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“…Moreover, for each diffusing cation, the barriers are inversely proportional to the spinel lattice parameter, leading to relative barriers for cation diffusion of When the carbon oxidizes over the CuFe 2 O 4 (100) surface, it was found that carbon was in favor of adsorbing on the O- terminated surface; therefore, the lattice O was easily released to generate CO x . 94 In addition, a mechanistic investigation of the influence of oxygen vacancies and sulfur poisoning on the reaction of spinel CuFe 2 O 4 with CO indicated that the oxygen vacancy and sulfur poisoning could weaken the surface reactivity. 95,96 Furthermore, the oxygen vacancy and sulfur poisoning surfaces are also unfavorable for the CO oxidation process.…”

Section: Synergy Effects In Composite Oxygen Carriersmentioning

confidence: 99%

Review on the Theoretical Understanding of Oxygen Carrier Development for Chemical-Looping Technologies

Liu

Yang

2022

Energy Fuels

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Chemical-looping combustion (CLC) is a novel and promising low-cost CO2 separation technology. The development of an oxygen carrier with high performance is the key to the successful application of CLC. Since it is still challenging for experimental measurements to acquire detailed information on the atomic mechanisms between the oxygen carrier and fuels or impurities. Alternatively, theoretical methods based on density functional theory (DFT) have become a powerful tool to study the electronic and structural properties of materials, as well as to clearly reveal the underlying microscopic mechanisms, which is helpful to rationally design high-performance oxygen carriers. Hence, the application of DFT in understanding the mechanisms for oxygen carrier development during the chemical-looping process is reviewed. The reactivity and detailed reaction mechanism of oxygen carriers are summarized, and the interaction between various components and the synergy in oxygen carriers are revealed. Particularly, the influences of foreign components (e.g., inert supports and dopants), adsorbate interaction, and surface structure on the reactivity of oxygen carriers are comprehensively discussed. Most of the examples discussed are mainly concerned with the reaction characteristics on the oxygen carrier surfaces. DFT calculations performed to understand and predict variations in reactivity from one oxygen carrier to another are emphasized. Moreover, the DFT method can also be employed to evaluate and screen oxygen carriers with appropriate properties including resistance to sintering, selectivity for production, and so forth. Finally, tentative future works on essential challenges and possible opportunities of understanding chemical-looping technology based on DFT calculations are preliminarily provided.

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“…4 As a kind of spinel structure materials, MFe 2 O 4 (M = Ni, Cu, Mn and Co) possess preferable redox activity than singlecomponent oxygen carriers (eg, Fe 2 O 3 , NiO, CuO). [5][6][7][8][9][10] Among the MFe 2 O 4 oxygen carriers, NiFe 2 O 4 has been studied extensively in Chemical Looping Gasification, [11][12][13][14] Chemical Looping Reforming, 9,15,16 Chemical Looping Combustion (CLC) [17][18][19] and Chemical Looping Hydrogen Generation (CLHG). [20][21][22] However, pure NiFe 2 O 4 exhibits low cycling stability caused by phase segregation in chemical looping reactions.…”

Section: Introductionmentioning

confidence: 99%

“…In the past 10 years, nearly 1200 kinds of oxygen carriers have been developed and evaluated 4 . As a kind of spinel structure materials, MFe 2 O 4 (M = Ni, Cu, Mn and Co) possess preferable redox activity than single‐component oxygen carriers (eg, Fe 2 O 3 , NiO, CuO) 5‐10 . Among the MFe 2 O 4 oxygen carriers, NiFe 2 O 4 has been studied extensively in Chemical Looping Gasification, 11‐14 Chemical Looping Reforming, 9,15,16 Chemical Looping Combustion (CLC) 17‐19 and Chemical Looping Hydrogen Generation (CLHG) 20‐22 …”

Section: Introductionmentioning

confidence: 99%

Phase segregation mechanism of NiFe ₂ O ₄ oxygen carrier in chemical looping process

Zhang

2020

Int J Energy Res

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Summary NiFe2O4 presents high redox activity and good promoted application prospect in chemical looping processes. However, phase segregation caused by outward diffusion of Fe cations often lead to low cycling stability for NiFe2O4. In this study, the inherent mechanism of phase segregation for NiFe2O4 was investigated deeply. The results indicated that reduction degree exhibited significant influence on the phase segregation of NiFe2O4 in successive redox cycles. When NiFe2O4 was reduced to Ni and Fe3O4 in redox cycles, NiFe2O4 displayed stable redox activity without phase segregation. As the reduction degree reached to FeO and FeNi, a needle‐like structure with Fe enrichment was formed on the surface of the first cycled NiFe2O4. In the subsequent redox cycles with deep reduction degree, both severe phase segregation and deactivation were occurred for spent NiFe2O4 sample. It can be seen that phase segregation is the main reason for the deactivation of NiFe2O4 instead of surface sintering in redox cycles. The results of this work provide guidance for the development of NiFe2O4‐based oxygen carriers with high redox performance.

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Solid-solid reaction of CuFe2O4 with C in chemical looping system: A comprehensive study

Cited by 40 publications

References 54 publications

Band gap and oxygen vacancy engineering of honeycomb‐like CuFe₂O₄ spinels toward enhanced high infrared emissivity

Band gap and oxygen vacancy engineering of honeycomb‐like CuFe₂O₄ spinels toward enhanced high infrared emissivity

Review on the Theoretical Understanding of Oxygen Carrier Development for Chemical-Looping Technologies

Phase segregation mechanism of NiFe ₂ O ₄ oxygen carrier in chemical looping process

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Solid-solid reaction of CuFe2O4 with C in chemical looping system: A comprehensive study

Cited by 40 publications

References 54 publications

Band gap and oxygen vacancy engineering of honeycomb‐like CuFe2O4 spinels toward enhanced high infrared emissivity

Band gap and oxygen vacancy engineering of honeycomb‐like CuFe2O4 spinels toward enhanced high infrared emissivity

Review on the Theoretical Understanding of Oxygen Carrier Development for Chemical-Looping Technologies

Phase segregation mechanism of NiFe 2 O 4 oxygen carrier in chemical looping process

Contact Info

Product

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Band gap and oxygen vacancy engineering of honeycomb‐like CuFe₂O₄ spinels toward enhanced high infrared emissivity

Band gap and oxygen vacancy engineering of honeycomb‐like CuFe₂O₄ spinels toward enhanced high infrared emissivity

Phase segregation mechanism of NiFe ₂ O ₄ oxygen carrier in chemical looping process