Au/LaVO4 Nanocomposite: Preparation, Characterization, and Catalytic Activity for CO Oxidation

The size of the gold particles is a very important parameter to get active catalysts. This paper reports a novel colloidal deposition method to prepare Au/LaVO4 nanocomposite catalyst with monodispersed Au colloids and uniform LaVO4 nanoplates in nonpolar solvent. Monodispersed Au colloids with tunable size (such as 2, 5, 7, 11, 13, and 16 nm) and LaVO4 nanocrystals with well-defined shapes were pre-synthesized assisted with oleic acid/amine. During the following immobilization process, the particle size and shape of Au and LaVO4 were nearly preserved. As-prepared Au/LaVO4 nanocomposite showed high catalytic activity for CO oxidation at room temperature. Since sizes of gold particles were well-defined before the immobilization process, size effect of gold particles was easy to be investigated and the results show that 5-nm Au/LaVO4 nanocomposite has the highest activity for CO oxidation. This synthetic method can be extended further for the preparation of other composite nanomaterials.