Kinetic study of the reduction of cobalt(II) by carbon monoxide in an aqueous system

Abstract

A study of the catalyzed reduction of cobalt(II) to metal by carbon monoxide from aqueous, ammoniacal solutions between 180 and 230 °C and from 0 to 50 atm CO is reported.The reaction proceeds through the intermediate formation of a cobalt carbonyl anion. Under the conditions of this study this intermediate is produced homogeneously and also heterogeneously in the presence of cobalt sulfide. Metal formation occurs only in the presence of cobalt sulfide.The stoichiometry of the production of cobalt carbonyl anion is consistent with the equation[Formula: see text]Metal formation follows the stoichiometry of the equation[Formula: see text]A mechanism that is consistent with the kinetic observations is presented.