Deposition of Gold Nanoparticles on Niobium Pentoxide with Different Crystal Structures for Room‐Temperature Carbon Monoxide Oxidation

Abstract Nanoparticulate gold catalysts (NPGCs) supported on niobium oxides (Nb 2 O 5 ) were prepared by different deposition methods. Au nanoparticles (NPs) with a mean diameter of approximately 5 nm were deposited by conventional deposition methods, which include the deposition‐precipitation (DP) and deposition‐reduction (DR) methods, on layered‐type Nb 2 O 5 that possesses a deformed orthorhombic structure. Moreover, Au NPs with a mean diameter of approximately 2.7 nm could be deposited by the sol immobilization method on several crystalline forms of Nb 2 O 5 (deformed orthorhombic, pseudohexagonal, and orthorhombic). NPGCs deposited on deformed orthorhombic Nb 2 O 5 had a higher catalytic activity for CO oxidation. The temperature for 50 % CO conversion was 11 °C for 1 wt % Au/Nb 2 O 5 (deformed orthorhombic) prepared by the sol immobilization method, and the CO conversion was 91 % at 28 °C. As far as we know, this is the first report of highly active Au NPGCs (smaller than 3 nm in diameter) supported on Nb 2 O 5 . NPGCs supported on acidic metal oxides will expand the utilization of gold catalysts for new applications.