Low effective activation energies for oxygen release from metal oxides: evidence for mass-transfer limits at high heating rates.
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.
['Jian|Guoqiang|G|', 'Zhou|Lei|L|', 'Piekiel|Nicholas W|NW|', 'Zachariah|Michael R|MR|']
activation energy metal oxides high heating rates isoconversion nanoparticles