Dehydrogenation of isopropyl alcohol over CoNi/Mg oxide catalysts

Abstract

Catalytic dehydrogenation of isopropyl alcohol was studied over Co₃O₄NiO/MgO catalysts containing 20 wt% of Co₃O₄ and NiO, or mixture of both oxides with different molar ratios. Catalysts were prepared from the corresponding nitrates (i.e. Co(NO₃)₂·6H₂O and Ni(NO₃)₂·6H₂O) and supported on MgO. Catalyst precursors were examined by TG, DTG and DTA, and were calcined between 500–700°C for 5 h in air. The surface area of these samples were calculated using the BET method. Those catalysts calcined at 500°C were characterized by XRD analysis. The amount of excess surface oxygen for these catalysts was calculated iodometrically. Basicity measurements were estimated by the adsorption of acidic molecules using pulse technique method. The vapour-phase dehydrogenation of isopropyl alcohol (IP), has been carried out over the catalysts calcined between 500–700°C. All catalysts showed 99.5% selectivity towards acetone formation. A correlation between the catalytic activity and the basicity of these catalysts has been made. The activation energy and the order of the dehydrogenation reaction of IP over some catalysts are given.