Autocatalytic Kinetics and Mechanism of the Reduction of Crystalline Cobalt Molybdate in hydrogen
Reduction of α-CoMoO4 in hydrogen results in the formation of Co2Mo3O8 and Co2MoO4. Its kinetics as measured in a vacuum microbalance and in a X-ray high temperature camera is first order with respect to hydrogen and follows sigmoidal curves. These are well described by the equation of an autocatalytic reaction in a shrinking sphere model dx/dt = k1 /(l+k2x). p(H2) . S. (1-x)3/2with activation energy 28.2 kcal/mole. The autocatalytic effect is due to traces of metallic cobalt forming in the course of reaction and activating hydrogen, the reduction then proceeding through a spillover effect.
KeywordsHydrogen Pressure Dissociative Adsorption Autocatalytic Reaction Metallic Cobalt Sigmoidal Curf
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