Effect of the acid-base properties of the support on the performance of Pt catalysts in the partial hydrogenation of citral

In this work, the effect that mesoporous solid materials, with different acid-base properties (Pt-1 wt%/acid or base) have over the product distribution during the partial hydrogenation of citral was evaluated. It was found that basic materials were the most active catalysts reaching a 100% citral conversion after 1 h of reaction. Regarding selectivity, in basic materials (Pt/MgAl-c and Pt/MgAl-r) citronellal was the main product, while nerol and geraniol were produced in acid solids (Pt/SiO2; Pt/SiO2-TiO2 and Pt/SiO2-ZrO2). The formation of unsaturated alcohols is related to the strength and density of the acid sites of the catalyst and in this sense the Pt/SiO2-ZrO2 gave a yield of 80%. The acidity trend is: Pt/SiO2-ZrO2 > Pt/SiO2-TiO2 > Pt/SiO2 > Pt/MgAl-c. (C) 2013 Elsevier B. V. All rights reserved.