Hydrogenation of α, β‐Unsaturated Aldehydes and Ketones on New AlPO₄‐Supported Nickel Catalysts

The liquid phase catalytic hydrogenation of Acrolein (A) and Methyl‐vinylketone (MVK) were studied over a series of new nickel catalysts supported on AlPO 4 , and AlPO 4 ‐Al 2 O 3 and AlPO 4 ‐SiO 2 systems, in methanol as solvent, at initial hydrogen pressure of 4.1 bar and temperatures between 298‐323 K. The hydrogenation of the C‐C double bond, yielding propanal or butanone were obtained in a first step at a yield of 100% because the reduction of butanone was not possible and, in the acrolein hydrogenation a kinetically consecutive process, acrolein → propanal → 1‐propanol, was obtained and 1‐propanol appeared just after acrolein was finished. The C‐C double bond of acrolein was hydrogenated more slowly than it was in methyl‐vinyl‐ketone. This result is probably due to an electronic effect of substitution from the methyl group. Moreover, the catalytic activity varies markedly with the support and was found to diminish as the nickel content decreased. The order of decreasing activity for the C‐C double bond: Ni/AlPO 4 ‐SiO 2 > Ni/AlPO 4 > Ni/AlPO 4 ‐Al 2 O 3 is valid for the hydrogenation of both substrates and it is associated with an effect of metal‐support interaction.