EFFECT OF METAL-SUPPORT INTERACTION DURING SELECTIVE HYDROGENATION OFCINNAMALDEHYDE TO CINNAMYL ALCOHOL ON PLATINUM-BASED BIMETALLIC CATALYSTS

The ethylenic unsaturation of alpha-beta ethylenic aldehydes is much m ore reactive to catalytic hydrogen addition than the carbon-oxygen dou ble bond, giving saturated aldehydes in a first step. Fortunately, in a liquid phase hydrogenation, the selectivity to the unsaturated alcoh ols may be improved by the choice of appropriate solvents and bimetall ic catalysts. In this work much attention has been brought to the fact ors that allow to achieve the best possible selectivity to cinnamyl al cohol. An oxide known to give special metal-support interaction, namel y TiO2, was chosen as our support. A careful study of the precursor re duction by TPR was a valuable guide to establish the final preparation for the active phase. The catalyst precursor was dried and reduced in an electric furnace under a flow of gas at atmospheric pressure. Comp ared to Pt, Pt-Sn and Pt-Fe on carbon, a monometallic Pt/TiO2 catalyst gives an excellent selectivity but a rather poor activity, Finally a selectivity to cinnamyl alcohol as high as 97% and a high activity are reached by using a bimetallic Pt-Fe/TiO2. This good selectivity has b een attributed to the metal support interaction.