Mesostructured Au/C materials obtained by replication of functionalized SBA-15 silica containing highly dispersed gold nanoparticles

The preparation and characterization of highly dispersed gold nanoparticles in ordered mesoporous carbons CMK-3 are reported. These carbons were obtained using gold-containing functionalized SBA-15 silicas as hard templates. Two series of Au/SiO2 templates were prepared, depending on the nature of the functionalization molecule. While ammonium-functionalized silicas gave gold particles with a size determined by the pores of the silica support, the use of mercaptopropyltrimethoxysilane as grafting molecule afforded the possibility to control the particle size inside the mesopores. Both series gave highly ordered mesoporous carbons with gold particles incorporated in the carbon nanorods. However, the gold particle size in mesoporous carbons was the same for both series and apparently did not depend on the nature of the silica template. Both Au/SiO2 templates and their corresponding Au/CMK-3 materials have been characterized by X-ray diffraction, nitrogen adsorption/desorption, chemical analysis, solid-state nuclear magnetic resonance and transmission electron microscopy. They were also used as catalysts in the aerobic oxidation of cyclohexene and trans-stilbene in the liquid phase.

Mesostructured carbons containing highly dispersed gold nanoparticles can be obtained by replication of functionalized mesoporous silicas SBA-15Figure optionsDownload as PowerPoint slideResearch highlights
► Gold particle size can be controlled by the porosity of silica supports such as SBA-15.
► Gold-supported mesostructured carbons have been obtained by replication of functionalized mesoporous silicas.
► The gold particle size in carbon replicas depends essentially on the porosity of the silica host.
► Gold-containing mesoporous carbons catalyze the oxidation of substrates with molecular oxygen.