X-ray photoelectron spectroscopy and infrared spectroscopy studies for the mechanism of the enantioselective hydrogenation of methyl acetoacetate over mixed nickel–cerium oxides Original Research Article

Mixed nickel cerium oxides have been used for studying the enantioselective hydrogenation of methyl acetoacetate (MAA) in methyl (3)-hydroxybutyrate (MHB). X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR) provide interesting information about the adsorption of both the reagent and the modifying agent (viz: tartaric acid). From the XPS results, we can assume that the presence of Ce3+ species, the amount of which is depending on the Nickel extent, stabilises a complex tartarate salt. The whole information lead to a new model with a stable six-membered cycle, in which the methylenic group of the reagent is involved.