Aluminas with different acidity were used as supports for Pt- and Pd-based catalysts. The Pt catalysts showed no significant difference in catalytic activity due to the acidity of alumina, but did record an enormous difference in selectivity. The Pt/Al2O3 basic catalyst showed total selectivity to diisopropyl-ether. On the other hand, Pd catalysts recorded different catalytic activity due to the acidity of the supports; the Pd/Al2O3 weakly acid catalyst performed better than acid and basic supports in the Pd-based catalysts. Otherwise, the sample of Pt-Pd/Al2O3 weakly acid catalyst showed complete selectivity towards propene. A comparison of the catalytic activity between bimetallic catalysts and the Pt-based catalysts revealed that it is lower for Pt-Pd-based catalysts and occurs at a higher temperature. (C) 2012 Elsevier Ltd. All rights reserved.