A Sol-Gel Route for the Preparation of Co3O4 Catalyst for Oxygen Electrocatalysis in Alkaline Medium

In order to increase the surface area of oxide electrocatalysts we have studied a new preparation method for Co3O4 spinel-type oxides. We have employed a sol-gel route, where the solution of Co(II)-carbonate in propionic acid is heated to form a resinic cobalt propionate. The powder obtained after pouring liquid nitrogen on the gel is immediately thermically treated up to 260°C to obtain the spinel pure phase Co3O4, as confirmed by X-ray diffractometry. SEM studies have shown that this precursor phase is near to mono-disperse with 2-4 μm particle size. The oxide obtained this way has a BET surface area higher than the oxides prepared by the nitrate decomposition route. However, taking into account the roughness factor, the electrocatalytic activities are similar.