Spatial evolution characteristics of active components of copper-iron based oxygen carrier in chemical looping combustion

Liu, Fang; Zhao, Jiangyuan; Xuan, Guohui; Zhang, Fan; Yang, Li

doi:10.1016/j.fuel.2021.121650

Cited by 23 publications

(4 citation statements)

References 38 publications

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“…Although the majority of research on OC has been experimental, there is an emerging trend to complement experimental findings with theory calculations. 53 Computational approaches are becoming increasingly important in CL research. Density function theory (DFT) calculations can be extended qualitatively to macroscopic redox reactions.…”

Section: In Situ Characterizationmentioning

confidence: 99%

“…For example, through the methods that explored the slitting oxygen carrier, the addition of TiO 2 significantly enhanced the ionic diffusivity of the O anion inside the OC . Using XPS, Liu et al explored the spatial evolution characteristics of active components from an OC’s cross section. It was also reported that the inward Cu migration was verified by the higher Cu/Fe ratio inside the used particle than that inside the fresh one from SEM-EDX images of cross-cut OC particles at different redox cycles .…”

Section: Advanced Technology For Exploring the Chemical Looping React...mentioning

confidence: 99%

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Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Song

Lin

et al. 2023

Energy Fuels

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Chemical looping technology is one of the most promising approaches in the fields of fuel conversion, pollution removal, energy conservation, and carbon dioxide capture and utilization and has been extensively investigated for more than two decades. A majority of the chemical looping process is achieved through the migration and transformation of lattice oxygen. Thus, exploring the migration and transformation of lattice oxygen is critical to clarify chemical looping’s reaction rules to allow for further control of reaction selectivity and yield. Herein, recent advances in the exploration of lattice oxygen’s migration mechanism are systematically reviewed, with a focus on structure–activity relationships. The great roles that characterization techniques perform to address the challenges in exploring the migration mechanism of lattice oxygen activities are discussed first. We then outline the categories of oxygen carrier materials and the migration mechanism of lattice oxygen. Lastly, the most promising research directions that design high-performance oxygen carriers with well-regulated lattice oxygen activity through the redox reaction mechanism are overviewed. We infer that the research on the relationship between lattice oxygen activity and target products is challenging but essentialit is a direction worthy of our efforts in the future.

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Section: In Situ Characterizationmentioning

confidence: 99%

Section: Advanced Technology For Exploring the Chemical Looping React...mentioning

confidence: 99%

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Song

Lin

et al. 2023

Energy Fuels

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“…As shown in Figure S1c (see configuration 3), this CFO configuration consists of two layers of Fe and Cu atoms, which are alternately distributed under the lattice direction. 21 Regarding this, we might propose the hypothesis that when adopting different CFO configurations, current observations associated reaction mechanisms (i.e., CO reaction pathways, sulfur resistance abilities, oxygen vacancy formation energies, the oxygen migration barriers, etc.) would present a significant difference.…”

Section: Introductionmentioning

confidence: 99%

Unraveling the Structure–Reactivity Relationship of CuFe₂O₄ Oxygen Carriers for Chemical Looping Combustion: A DFT Study

Tang

Sun

et al. 2023

Energy Fuels

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CuFe2O4 is an emerging high-performance oxygen carrier for chemical looping combustion (CLC), which is hailed as the most promising technology to reduce combustion-derived CO2 emission. CuFe2O4 oxygen carriers with minute structural differences could be largely divergent in the reactivity for the CLC process, which seems not to raise much concern by either experimental or computational studies. Herein, based on density functional theory (DFT) calculations, we compare the performance of three well-documented CuFe2O4 configurations as oxygen carriers in the CLC process and relate the reactivity difference to their structural nuances. The reaction mechanisms of representative CLC reactants (i.e., CH4, H2, and CO) over different CuFe2O4 configurations are explored in-depth. DFT calculations indicate that among different CuFe2O4 configurations, the distribution, orientation, and activity of the O/Cu/Fe sites vary largely over the respective CuFe2O4(100) surfaces, thus affecting the adsorption and oxidation of CLC reactants. Fe atoms, especially in configuration 3, are observed to exhibit a higher degree of exposure and afford lower steric hindrance to interact with CH4 and H2, thereby facilitating higher adsorption energies and lower dissociation energy barriers correspondingly. The Fe–Cu synergistic effect is revealed to promote the dissociation reaction of both CH4 and H2. CO exhibits direct oxidation to CO2 over the O sites, which generally exhibit higher CO binding energies than Cu/Fe sites. Particularly, O sites in configuration 3 are observed with generally lower oxygen vacancy formation energy as well as steric hindrance, thus affording the oxidation of CO in a more facile way. The structure–performance relationship revealed in this work is of positive significance for the design of high-performance spinel CuFe2O4 oxygen carriers.

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“…As a major climate forcing factor, CO 2 mainly generated from fossil fuel combustion and coal-fired power stations are the largest source of CO 2 emissions (Cui et al 2021;Leng et al 2021;Liu et al 2021). At present, controlling the emission of CO 2 is a key challenge for China to achieve the peak carbon in 2030.…”

Section: Introductionmentioning

confidence: 99%

Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure

Lin

Xue

Tao

et al. 2023

Int J Coal Sci Technol

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The critical issue in developing mature Oxy-Coal Combustion Steam System technology could be the reactivity of demineralized coal which, is closely related to its chemical structure. The chemical structures of Liupanshui raw coal (LPS-R) and Liupanshui demineralized coal (LPS-D) were analyzed by FTIR and solid-state 13C-NMR. The pyrolysis experiments were carried out by TG, and the pyrolysis kinetics was analyzed by three iso-conversional methods. FTIR and 13C-NMR results suggested that the carbon structure of LPS coal was not altered greatly, while demineralization promoted the maturity of coal and the condensation degree of the aromatic ring, making the chemical structure of coal more stable. The oxygen-containing functional groups with low bond energy were reduced, and the ratio of aromatic carbon with high bond energy was increased, decreasing the pyrolysis reactivity. DTG curve-fitting results revealed that the thermal weight loss of LPS coal mainly came from the cleavage of aliphatic covalent bonds. By pyrolysis kinetics analysis of LPS-R and LPS-D, the apparent activation energies were 76 ± 4 to 463 ± 5 kJ/mol and 84 ± 2 to 758 ± 12 kJ/mol, respectively, under different conversion rates. The reactivity of the demineralized coal was inhibited to some extent, as the apparent activation energy of pyrolysis for LPS-D increased by acid treatment.

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Spatial evolution characteristics of active components of copper-iron based oxygen carrier in chemical looping combustion

Cited by 23 publications

References 38 publications

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Unraveling the Structure–Reactivity Relationship of CuFe₂O₄ Oxygen Carriers for Chemical Looping Combustion: A DFT Study

Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure

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Spatial evolution characteristics of active components of copper-iron based oxygen carrier in chemical looping combustion

Cited by 23 publications

References 38 publications

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Review on Migration and Transformation of Lattice Oxygen during Chemical Looping Conversion: Advances and Perspectives

Unraveling the Structure–Reactivity Relationship of CuFe2O4 Oxygen Carriers for Chemical Looping Combustion: A DFT Study

Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure

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Unraveling the Structure–Reactivity Relationship of CuFe₂O₄ Oxygen Carriers for Chemical Looping Combustion: A DFT Study