HYDROGENATION OF SUBSTITUTED ACROLEIN OVER ALUMINA-SUPPORTED RUTHENIUM CATALYSTS

The gas phase hydrogenation of acrolein, 2-methyl-2-propenal, 2-butena l and 3-methyl-2-butenal was studied on Ru/Al2O3 and RuM/Al2O3 catalys ts (M = Sn, Fe, Zn, Ge, Sb). The specific activity increases when the second element is added to the parent Ru/Al2O3 catalyst. This was ascr ibed to the activation of the C=O bond by M(delta+) species. Tin is th e only additive which promotes the allyl alcohol selectivity. When met hyl groups are tagged on the C=C bond the selectivity to the unsaturat ed alcohol increased sharply due to the steric hindrance against the a dsorption of the substrate via the C=C double bond.