Preparation and catalytic activity in ethanol combustion reaction of cobalt–iron spinel catalysts

• Pure CoFe2O4 phase is obtained when NaOH and oxalate are the coprecipitation agents.
• Fe2O3 + CoFe2O4 mixture is obtained with the precipitation agent NH3.
• NaOH and NH3 precipitated cobalt ferrites are mesoporous.
• Oxalate precursor leads to nonporous cobalt ferrites.
• Formation of Fe2O3 within cobalt ferrites causes an activity loss.

Iron–cobalt spinel catalysts were prepared via the coprecipitation method. The effect of different parameters on textural, structural and catalytic properties, in ethanol combustion, was investigated. The CoFe2O4 phase was obtained at calcination temperatures as low as 500 °C and the usage of ammonia as precipitating agent, results in the formation of Fe2O3 in addition to the spinel phase. The catalyst prepared using nitrate salts, NaOH as precipitation agent and calcined at 600 °C had the best catalytic performance achieving ethanol complete oxidation at 271 °C.