title: Low effective activation energies for oxygen release from metal oxides: evidence for mass-transfer limits at high heating rates.
abstract: Oxygen release from metal oxides at high temperatures is relevant to many thermally activated chemical processes, including chemical-looping combustion, solar thermochemical cycles and energetic thermite reactions. In this study, we evaluated the thermal decomposition of nanosized metal oxides under rapid heating (~10(5) K s(-1)) with time-resolved mass spectrometry. We found that the effective activation-energy values that were obtained using the Flynn-Wall-Ozawa isoconversional method are much lower than the values found at low heating rates, indicating that oxygen transport might be rate-determining at a high heating rate.
authors.affiliation: Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (USA).
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Jian
authors.forename: Lei
authors.initials: L
authors.lastname: Zhou
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Piekiel
authors.forename: Michael R
authors.initials: MR
authors.lastname: Zachariah
keywords: activation energy; high heating rates; isoconversion; metal oxides; nanoparticles