| Abstract: | The heterogeneous oxidation of ammonium sulphite was investigated with cobalt sulphate catalyst at 30°C. For a wide range of concentrations the reaction was found to be nearly first order in oxygen and zero order in sulphite. These kinetics contrast with the results of homogeneous experiments which indicate that the reaction is zero order in oxygen and three-halves order in sulphite. The catalytic effect of cobalt ions was found to be proportional to the square root of the total concentration of cobalt. The apparent activation energy for the overall oxidation was calculated to be 13 kcal/g mol. It is concluded that the kinetics in the heterogeneous system are determined by the catalyst regeneration reaction which is diffusion controlled. |
