Solid State Kinetics for the Reduction of Cobalt Oxide
Luke J. Venstrom
The rate of reduction of Cobalt Oxide was measured using non-isothermal thermogravimetric experiments and the data were analyzed to elucidate reaction kinetic parameters. The data cover a range of experimental conditions, including heating rates from 5 to 15 °C/s, oxygen partial pressures from 0 to 0.2 bar, and mean particle sizes of 0.08 and 4.0 µm. In all cases, the reduction follows the spherical shrinking core kinetic model with two rate limiting steps: the conversion of at the reaction interface and gas phase diffusion of away from the external particle surface. The Arrhenius equation was applied to model the temperature dependence of the kinetic parameters. The activation energy and natural log of the pre-exponential factor for the interface reaction step averaged 985 kJ/mole and 41 ln(1/s) for the 0.08 µm particles and averaged 104 kJ/mole and 3 ln(1/s) for 4.0 µm. The activation energy and natural log of the pre-exponential factor for the gas phase diffusion step averaged 3215 kJ/mole and 141 ln(1/s) for the 0.08 µm particles and averaged 1470 kJ/mole and 64 ln(1/s) for 4.0 µm.
Hall, Ryan L., "Solid State Kinetics for the Reduction of Cobalt Oxide" (2014). Symposium on Undergraduate Research and Creative Expression (SOURCE). 379.