Low-temperature carbon monoxide and propane total oxidation by nanocrystalline cobalt oxidesReport as inadecuate

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1 CIRIMAT - Centre interuniversitaire de recherche et d-ingenierie des matériaux

Abstract : Pure CoOOH, with intra particulate porosity up to 76%, was synthesized by an innovative aqueous precipitation method, starting either from nitrate or sulfate salts. Microstructural and chemical properties were characterized by powder X-ray diffraction XRD, thermogravimetry TG and differential scanning calorimetry DSC, scanning electron microscopy SEM and high-resolution transmission electron microscopy HRTEM. The primary particles 10–15 nm are self-organized in monolayer building hexagonal nano-platelets 50–200 nm which are arranged randomly creating large pores. CoOOH was converted in Co3O4 by heating in air at 250 °C. This treatment did not modify the porosity but increased the specific surface area, which became close to 100 m2-g. The catalytic activity for CO and C3H8 total oxidation was better for Co3O4 than for CoOOH. Besides, at high conversion rate, catalysts prepared from sulfate precursor showed a superior activity for C3H8 oxidation than those prepared from nitrate. This effect can be explained by the improved accessibility of reactants to the surface of the catalysts which exhibit a larger porosity. To our knowledge, the activity values presented here are the highest reported in literature for C3H8 total oxidation.

Keywords : Cobalt oxides Precipitation method Catalysis Carbon monoxide CO oxidation Propane C3H8 oxidation

Author: Guillaume Salek - Pierre Alphonse - Pascal Dufour - Sophie Guillemet-Fritsch - Christophe Tenailleau -

Source: https://hal.archives-ouvertes.fr/


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