Hydrogenation of Carbonyl Compounds over Granulated Ni/Al₂O₃ Catalyst in a Flow Reactor

Hydrogenation of carbonyl compounds on highly dispersed granulated Ni/Al₂O₃ catalyst in a flow mode was studied. The catalyst precursor was prepared from an ammonia-carbonate complex by incipient wetness impregnation with subsequent drying and calcination stages. X-ray diffraction and transmission electron microscopy methods showed the formation of nickel oxide particles less than 5 nm in size on the alumina surface. This catalyst provides highly selective hydrogenation (selectivity >99.5%) of an aliphatic ketone (2-heptanone) to the corresponding alcohol with a substrate conversion of ~99%. In the case of aliphatic aldehyde (n-octanal), which has stronger electrophilic properties, the reaction proceeds with lower selectivity (96%) due to the formation of aldol condensation products. Unlike aliphatic compounds, the hydrogenation of aromatic aldehydes and ketones occurs with very low selectivity due to the hydrogenation of the aromatic ring and hydrogenolysis of the C—O bond.

Ni/Al₂O₃, granulated catalyst, hydrogenation, carbonyl compounds, flow reactor