Sangaré Kassoum^1,, Seyhi Brahima², Coulibaly Bamoro¹

The aim of the present study was to synthesize Mn_0.6Cu_0.4Co₂O₄ electrocatalyst powder using nanocasting method with KIT6-100 silica and to investigate its chemical and physicochemical properties. Nanocasting process induced high oxide specific surface areas to the electrocatalyst, with BET surface value of 132 m²/g. By comparison, 91 m²/g was obtained by the classic solgel method. Pore size distribution investigation revealed a mesoporous structuration of the electrocatalyst synthetized by nanocasting route. This led to uniform pore size of ca. 6.1 nm whereas, a large distribution from 2 to 50 nm was found for solgel method. The uniform and controlled pore size contributed to effective penetration of the liquid electrolyte. X-ray diffraction (XRD) study revealed spinel lattice structure with large crystallites of about 8 nm. X-ray photoelectron spectroscopy (XPS) measurements confirmed the presence of metal adsorption sites for electrocatalytic reactions. It also showed the predominance of Co²⁺, Cu²⁺ and Mn⁴⁺ species at the sample’s surfaces, beneficial for good intrinsic activities of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER).

electrocatalyst, spinel structure, nanocasting, solgel, specific surface area, pore size