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The kinetics of dry-methane reforming has been studied over a ceria-promoted Mo 2 C / γ - Al 2 O 3 (3 wt% Ce, 30 wt% Mo) catalyst at temperatures between 800 and 900 ∘ C , and at CH 4 and CO 2 partial pressures up to 0.31 bar. Oxidation of the Mo 2 C catalyst, which has plagued earlier kinetic studies, was avoided by co-feeding CO to produce a CO : CO 2 ratio of 3. The activation energy obtained from the data fit to a power law rate expression of 45.5 kcal/mol was found to be similar to that of bulk Mo 2 C . However, the activity of the ceria-promoted catalyst, on a per unit mass of Mo 2 C , was significantly higher than that of the bulk and is attributed to the higher metal dispersion of the former. A reaction mechanism, involving CH 4 activation on Mo 2 C particles and CO 2 activation on both ceria and Mo 2 C particles, with carbidic carbon extraction by oxygen on ceria as the rate-determining step, is consistent with the derived kinetic model and the high activation energy. |
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