Tracking the evolution of a single composite particle during redox cycling for application in H2 production

Dragos Neagu; Evangelos I. Papaioannou; Bernhard Tjaden; Xuekun Lu; Cheuk-Man Mak; Michael W. Gaultois; Brian Ray; Paul Shearing; Ian S. Metcalfe

doi:10.1038/s41598-020-62237-y

Tracking the evolution of a single composite particle during redox cycling for application in H₂ production

Dragos Neagu, Evangelos I. Papaioannou, Bernhard Tjaden, Xuekun Lu, Cheuk-Man Mak, Michael W. Gaultois, Brian Ray, Paul Shearing, Ian S. Metcalfe^*

^*Corresponding author for this work

Chemical And Process Engineering

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

23 Downloads (Pure)

Abstract

Composite materials consisting of metal and metal oxide phases are being researched intensively for various energy conversion applications where they are often expected to operate under redox conditions at elevated temperature. Understanding of the dynamics of composite evolution during redox cycling is still very limited, yet critical to maximising performance and increasing durability. Here we track the microstructural evolution of a single composite particle over 200 redox cycles for hydrogen production by chemical looping, using multi-length scale X-ray computed tomography. We show that redox cycling triggers a centrifugal redispersion of the metal phase and a centripetal clustering of porosity, both seemingly driven by the asymmetric nature of oxygen exchange in composites. Initially, the particle develops a large amount of internal porosity which boosts activity, but on the long term this facilitates structural and compositional reorganisation and eventually degradation. These results provide valuable insight into redox-driven microstructural changes and also for the design of new composite materials with enhanced durability.

Original language	English
Article number	5266
Number of pages	9
Journal	Scientific Reports
Volume	10
DOIs	https://doi.org/10.1038/s41598-020-62237-y
Publication status	Published - 24 Mar 2020

Funding

The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement Number 320725 and from the EPSRC via grants EP/K029649/1, EP/P007767/1, EP/P024807/1, EP/R023921/1, EP/M014045/1 and EP/ P009050/1, PRS acknowledges the support of the Royal Academy of Engineering. MWG thanks the Leverhulme Trust for funding via the Leverhulme Research Centre for Functional Materials Design. We thank Cambridge University, Department of Chemistry, for access to the X-ray Diffraction Facility.

Keywords

energy conversion applications
composite particle
redox cycling

Access to Document

10.1038/s41598-020-62237-yLicence: CC BY 4.0

Neagu-etal-SR-2020-Tracking-the-evolution-of-a-single-composite-particle-during-redox-cyclingFinal published version, 1.85 MBLicence: CC BY 4.0

Cite this

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AU - Mak, Cheuk-Man

AU - Gaultois, Michael W.

AU - Ray, Brian

AU - Shearing, Paul

AU - Metcalfe, Ian S.

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