VOx-based catalyst has been extensively used in catalysts for oxidation reactions, especially for the partial oxidation of alkanes. Our previous study showed that the VOx/Pt(111) surfaces are highly active for the complete oxidation of propane. In this article, SmO, was used as an additive for the VOx/Pt(111) model surfaces to improve the catalytic performance for the partial oxidation of C3H8. And Mo foil was used to replace Pt to examine the substrate effect on the VOx/SmOx. Ordered SmOx/Pt(111), VOx/SmOx/Pt(111), VOx/SmOx/Mo and VOx/Pt(111) were prepared under ultra-high-vacuum conditions and characterized using Auger electron spectroscopy, low-energy electron diffraction and high-resolution electron energy loss spectroscopy. The results show that the main product is CO2 with a small amount of CO on the Pt substrate. The SmOx layer on the Pt(111) surface or between VOx and Pt(111) suppresses the activities of both Pt and VOx/Pt, but enhances the selectivity to CO. Replacing Pt(111) with a Mo foil, VOx on SmOx/Mo shows a much lower activity, while achieves some selective product of propene. (C) 2014 Elsevier B.V. All rights reserved.