Oxidation Reduction Behavior of Iron-Bearing Olivines (FexMg1-x)2SiO4 Used as Catalysts for Biomass Gasification
Autor: | C. Courson, L. Bedel, A. Kiennemann, D. Świerczyński, Serge Vilminot |
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Rok vydání: | 2006 |
Předmět: | |
Zdroj: | Chemistry of Materials. 18:897-905 |
ISSN: | 1520-5002 0897-4756 |
DOI: | 10.1021/cm051433+ |
Popis: | Natural iron-bearing olivines (FexMg1-x)2SiO4 have been recognized as one of the most promising tar-cracking catalytic materials for fluidized bed biomass gasification to produce syngas (H2 + CO). Iron present in the olivine significantly influences its catalytic activity. However, the Fe0-active phase cannot be obtained by the reduction of olivine under the catalyst working conditions. A better understanding of olivine's behavior in oxidizing−reducing conditions is crucial for control of its catalytic properties. In this paper, we have demonstrated how the oxidation of iron-bearing olivines leads to the formation of reducible iron oxides dispersed in the iron-depleted olivine matrix. The choice of oxidation−reduction conditions permits us to control the amount of iron extracted from the olivine structure. The mechanism of the oxidation−reduction behavior of a natural olivine has been studied by 57Fe Mossbauer spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and temperature-progr... |
Databáze: | OpenAIRE |
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