In Situ Structural Variations of Individual Particles of an Al2O3-Supported Cu/Fe Spinel Oxygen Carrier During High-Temperature Oxidation and Reduction

  • W. H. Harrison NealleyEmail author
  • Anna Nakano
  • Jinichiro Nakano
  • James P. Bennett
Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


Physical and chemical degradation of the oxygen-carrier materials during high-temperature redox exposures may affect the overall efficiency of the chemical looping process. Therefore, studying real-time physical and chemical changes in these materials when exposed to repeated redox cycles is essential for further development of chemical looping technology. In this work, the National Energy Technology Laboratory’s Al2O3-supported Cu/Fe spinel oxygen carrier, in the form of a CuO · Fe2O3 solid solution, was examined in situ during 3-h exposures to either oxidizing or reducing environments at 800 °C using a controlled atmosphere heating chamber in conjunction with a confocal scanning laser microscope. A compilation of the physical changes of individual particles using a controlled atmosphere confocal microscope and the microstructural/chemical changes documented using a scanning electron microscope will be discussed.


Chemical looping Fossil energy Oxygen carrier 



This work was performed in support of the US Department of Energy’s Fossil Energy Advanced Combustion Program. The research was executed through NETL Research and Innovation Center’s Advanced Combustion effort. Research performed by AECOM Staff was conducted under the RES contract DE-FE-0004000. The authors wish to thank Mr. Matt Fortner for metallography.

Figure 1 reprinted with permission from Nealley et al.: Springer, JOM, Structural changes and material transport in Al2O3-supported Cu/Fe spinel particles in a simulated chemical looping combustion environment, Nealley WHH, Nakano A, Nakano J, Bennett JP, Copyright (2018).

The authors declare that they have no competing financial interest.


This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.


  1. 1.
    Metz B, Davidson OR, Bosch PR, Dave RL, Meyer A (eds) (2007) Mitigation. Contribution of working group III to the fourth assessment report of the intergovernmental panel on climate change, IPCC, 2007. Cambridge University Press, CambridgeGoogle Scholar
  2. 2.
    Hossain MM, de Lasa HI (2008) Chemical-looping combustions (CLC) for inherent CO2 separations—a review. Chem Eng Sci 63:4433–4451CrossRefGoogle Scholar
  3. 3.
    Nealley WHH, Nakano A, Nakano J, Bennett JP (2018) Structural changes and material transport in Al2O3-supported CuFe2O4 particles in a simulated chemical looping combustion environment. JOM 70(7):1232–1238CrossRefGoogle Scholar
  4. 4.
    Lyngfelt A (2011) Oxygen carriers for chemical looping combustion—4000 h of operational experience. Oil Gas Sci Tech 66:161–172CrossRefGoogle Scholar
  5. 5.
    Wang X, Chen Z, Hu M, Tian Y, Jin X, Ma S, Xu T, Hu Z, Liu S, Guo D, Xiao B (2017) Chemical looping combustion of biomass using metal ferrites as oxygen carriers. Chem Eng J 312:252–262CrossRefGoogle Scholar
  6. 6.
    Voitic G, Hacker V (2016) Recent advancements in chemical looping water splitting for the production of hydrogen. RSC Adv 6:9867–9896Google Scholar
  7. 7.
    Hu W, Donat F, Scott SA, Dennis JS (2016) The interaction between CuO and Al2O3 and the reactivity of copper aluminates below 1000 °C and their implication on the use of the Cu–Al–O system for oxygen storage and production. RSC Adv 6:113016–113024CrossRefGoogle Scholar
  8. 8.
    Liu W, Ismail M, Dunstan MT, Hu W, Zhang Z, Fennell PS, Scott SA, Dennis JS (2015) Inhibiting the interaction between FeO and Al2O3 during chemical looping production of hydrogen. RSC Adv 5:1759–1771CrossRefGoogle Scholar
  9. 9.
    Bayham S, Straub D, Weber J (2017) Operation of the NETL chemical looping reactor with natural gas and a novel Copper-Iron material. NETL-PUB-20912; NETL technical report series; U.S. Department of Energy, National Energy Technology Laboratory, Morgantown, WVGoogle Scholar
  10. 10.
    Siriwardane R, Riley J, Bayham S, Straub D, Tian H, Weber J, Richards G (2018) 50-kWth methane/air chemical looping combustions tests with commercially prepared CuO–Fe2O3-alumina oxygen carrier with two different techniques. App Energy 213:92–99CrossRefGoogle Scholar
  11. 11.
    Wang B, Yan R, Zhao H, Zheng Y, Liu Z, Zheng C (2011) Investigation of chemical looping combustion of coal with CuFe2O4 oxygen carrier. Energy Fuels 25:3344–3354CrossRefGoogle Scholar
  12. 12.
    Wang B, Ma Q, Wang W, Zhang C, Mei D, Zhao H, Zheng C (2017) Effect of reaction temperature on the chemical looping combustions of coal with CuFe2O4 combined oxygen carrier. Energy Fuels 31:5233–5245CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2019

Authors and Affiliations

  • W. H. Harrison Nealley
    • 1
    • 2
    Email author
  • Anna Nakano
    • 1
    • 3
  • Jinichiro Nakano
    • 1
    • 3
  • James P. Bennett
    • 1
  1. 1.U.S. Department of Energy National Energy Technology LaboratoryAlbanyUSA
  2. 2.Oak Ridge Institute for Science and EducationOak RidgeUSA
  3. 3.AECOMSouth ParkUSA

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