Mechanistic insights on the preparation of 5-methyl-2-hexanone by hydrogenation of 5-methyl-3-hexen-2-one using Pd/AlO catalysts.

5-methyl-2-hexanone is used as a versatile polymerization solvent for industrial preparation processes of bulk and fine chemicals. An efficient catalyst, Pd/γ-AlO, is reported for the preparation of 5-methyl-2-hexanone by selective hydrogenation of 5-methyl-3-hexen-2-one. The catalyst exhibits remarkable activity and selectivity even at atmospheric pressure and low temperature (1 atm, 80 °C). The influence weight of reaction conditions on the reaction process was obtained through the Artificial Neural Network model, which were reaction pressure, reaction temperature and liquid hourly space velocity in order. The reaction kinetics and mechanism of 5-methyl-2-hexanone preparation by hydrogenation over Pd/γ-AlO catalyst were investigated. The hydrogenation reaction pathway of 5-methyl-3-hexen-2-one was obtained by using Density functional theory calculations, and the mechanism of selective hydrogenation of CC double bonds and CO double bonds was revealed. A kinetic model based on the LHHW model assumption was also proposed and compared with experimental results demonstrating good predictability.