Cobalt powder from Co(OH)2 by hydrogen reduction

A study was performed to prepare spherical cobalt powder of about 400 nm from aqueous cobaltous hydroxide slurry under hydrogen reduction conditions using palladium chloride as a catalyst. The reduction kinetics showed good agreement with a surface reaction core model equation, and the activation energy of 35.6 kJ/mol was obtained from the Arrhenius plot at the temperature range of 145–195°C. Additionally, a relationship between the half-life of the reduction, the induction period, and the hydrogen gas pressure was found to be as t1/2−ti=aPH21−n.