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 (Nb2O5) 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 Nb2O5 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 Nb2O5 (deformed orthorhombic, pseudohexagonal, and orthorhombic). NPGCs deposited on deformed orthorhombic Nb2O5 had a higher catalytic activity for CO oxidation. The temperature for 50 % CO conversion was 11 °C for 1 wt % Au/Nb2O5 (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 Nb2O5. NPGCs supported on acidic metal oxides will expand the utilization of gold catalysts for new applications.

Lewis Acid Catalysis of Nb2O5 for Reactions of Carboxylic Acid Derivatives in the Presence of Basic Inhibitors

“…In addition to the applications of Nb‐based oxides as heterogeneous catalysts, they may also be used as effective support materials. The presented properties, which include the activation of C=O moieties in carboxylic acid derivatives and high base tolerance, should also be attractive features for this purpose …”

“…The presented properties, which include the activation of C=O moieties in carboxylic acid derivatives and high base tolerance, should also be attractive features for this purpose. [92][93][94][95] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57…”

Carbon Monoxide Oxidation by Polyoxometalate‐Supported Gold Nanoparticulate Catalysts: Activity, Stability, and Temperature‐ Dependent Activation Properties

“…Sol immobilization was performeda ccording to the previous report [28] with slight modification. Adark brown solution of thiolateprotected gold colloids dissolved in 15 mL of toluene was added dropwise into as olution of Cs-SiW dispersed in 10 mL of toluene.…”

Carbon Monoxide Oxidation by Polyoxometalate‐Supported Gold Nanoparticulate Catalysts: Activity, Stability, and Temperature‐ Dependent Activation Properties

“…Sol immobilization was performed according to the previous report with slight modification. A dark brown solution of thiolate‐protected gold colloids dissolved in 15 mL of toluene was added dropwise into a solution of Cs‐SiW dispersed in 10 mL of toluene.…”