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Reduction of iron oxide catalysts: the investigation of kinetic parameters using rate perturbation and linear heating thermoanalytical techniques

Tiernan, M. J., Barnes, Philip A. and Parkes, Gareth M.B (2001) Reduction of iron oxide catalysts: the investigation of kinetic parameters using rate perturbation and linear heating thermoanalytical techniques. Journal of Physical Chemistry B, 105. pp. 220-228. ISSN 1089-5647

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    Abstract

    The mechanisms and kinetics of the reduction of powdered Fe2O3 and Fe3O4 samples have been investigated under nonisothermal conditions to provide a detailed insight into the processes occurring. Both conventional linear heating temperature-programmed reduction (TPR) and constant rate temperature-programmed reduction (CR-TPR) techniques were utilized. Fe2O3 was found to reduce to Fe in a two-step process via Fe3O4. The mechanism of the prereduction step of Fe2O3 to Fe3O4 was found to follow an nth order expression where nucleation or diffusion was not the rate-controlling factor while the main reduction step to metal was described by a model involving the random formation and growth of nuclei. A CR-TPR rate perturbation method, "rate-jump", was applied to the measurement of variations in apparent activation energy throughout the reduction processes, under near-equilibrium conditions and the activation energy measurements are compared with those obtained under conventional linear heating conditions.

    Item Type: Article
    Additional Information: Copyright © 2007 American Chemical Society
    Uncontrolled Keywords: Iron oxide catalysts
    Subjects: Q Science > QD Chemistry
    Schools: School of Applied Sciences
    School of Applied Sciences > Materials and Catalysis Research Centre
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    References:

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    Depositing User: Briony Heyhoe
    Date Deposited: 12 Jul 2007
    Last Modified: 28 Jul 2010 19:20
    URI: http://eprints.hud.ac.uk/id/eprint/193

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