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 alpha-MoO3 and alpha-NiMoO4 thin films; for most bilayer materials, an additional phase, beta-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.