Crotonaldehyde hydrogenation over clay-supported platinum catalysts

Two clay-supported platinum catalysts were prepared by impregnation and tes ted in the liquid phase hydrogenation of crotonaldehyde. Over both catalyst s, the unsaturated alcohol selectivity was increased (to 49%) compared to t hat obtained over platinum on conventional supports (maximum 20%). The effe ct of the solvent, the subtrate initial concentration, the hydrogen pressur e and the reaction time was studied. The benefic effect of the support was observed only if an alcohol was used as solvent. A deuterium tracer study r evealed the coaction of the Lewis acid sites of the clay supports in adsorp tion of the substrate leading to an increase in the crotyl alcohol selectiv ity. The self poisoning of the metal over the clay-supported catalysts was supposed to inhibit the C=C group hydrogenation. (C) 2001 Elsevier Science B.V. All rights reserved.