Multicomponent thin film molybdate catalysts for the selective oxidation of 1,3-butadiene

The selective oxidation of 1,3-butadiene was examined over single and multiphase NiMoO₄-MoO₃ thin film catalysts prepared by reactive sputtering. Previous studies of precipitated catalysts have indicated that synergism occurs for these multicomponent materials: sputtered films behaved similarly but tended to be more active and selective. XRD, LRS, XRF, XPS, SEM, and TEM were used to characterize the α-MoO₃ and α-NiMoO₄ thin films; for most bilayer materials, an additional phase, β-NiMoO₄, was present in an interfacial region. Selectivity for furan, 2(5H)-furanone, and maleic anhydride was enhanced by the preparation of the materials as layered films.