Ultrasound effect in the synthesis of catalysts of cobalt oxides prepared starting from the coprecipitation method of a hydrotalcite structure was evaluated in this work and characterized by DRX, FRX, BET, TPR and TPO. It is found that catalytic conversion of butanol on the Co-Mg-Al mixed oxides prepared by ultrasound method (10 min) is higher than that on the Co-Mg-Al mixed oxides prepared by conventional treatment (24 h). The surface area and the butanol oxidation are linearly related to the content of the hydrotalcite-like phase in the precursor, which resulted in highly dispersed Co (Co2+), MgO and Al2O3 particles in the final catalyst. Similarly, the use of ultrasound in the synthesis reveals a benefic effect in so far as similar solids are obtained in much less time. The catalysts show greater activity and selectivity to CO2 and H2O than the commercial ones. (C) 2010 Elsevier B.V. All rights reserved.