Superior catalytic properties in aerobic oxidation of olefins over Au nanoparticles on pyrrolidone-modified SBA-15

• Published in: Journal of catalysis 2011-07, Vol.281 (1), p.30-39
• Main Authors: Wang, Liang, Wang, Hong, Hapala, Prokop, Zhu, Longfeng, Ren, Limin, Meng, Xiangju, Lewis, James P., Xiao, Feng-Shou
• Format: Article
• Language: English
• Subjects: atmospheric pressure; Au nanoparticles; carbon; Catalysis; Catalysts; Chemistry; Colloidal state and disperse state; Cyclohexene and styrene oxidation by molecular oxygen; cyclohexenes; Exact sciences and technology; General and physical chemistry; gold; image analysis; infrared spectroscopy; nanogold; Nanoparticles; nitrogen; nuclear magnetic resonance spectroscopy; oxidation; oxygen; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Porous materials; Pyrrolidone; sorption isotherms; stable isotopes; styrene; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; transmission electron microscopy; X-ray diffraction; X-ray photoelectron spectroscopy
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2011.03.029

Au nanoparticles highly dispersed in the mesopores of pyrrolidone (Py)-modified SBA-15 (Au/SBA-15-Py) are efficient and stable heterogeneous catalysts for oxidations of cyclohexene and styrene by molecular oxygen at atmospheric pressure. The interaction between Au nanoparticles with Py in Au/SBA-15-Py is supported by XPS characterization, in strong agreement with density-functional theory calculations. [Display omitted] ► Au nanoparticles are highly dispersed in the mesopores of pyrrolidone-modified SBA-15 ►. Au/SBA-15-Py has excellent catalytic properties in aerobic oxidation of olefins. ► There is an interaction between Au nanoparticles with Py species. ► The interaction was studied by density-functional theory calculations. We report on our systematic investigation of Au nanoparticles highly dispersed in the mesopores of (s)-(–)-2-pyrrolidinone-5-carboxylic acid (Py)-modified SBA-15 (Au/SBA-15-Py) by using a series of modern techniques. 13C NMR and IR spectroscopies indicate that Py species are successfully grafted on the surface of mesopores in SBA-15; XRD patterns and N 2 adsorption isotherms show that the sample mesostructures are well preserved; TEM images clearly confirm the uniform Au nanoparticles in the mesopores; and XPS suggests an interaction between Au nanoparticles with Py species. Interestingly, Au/SBA-15-Py catalysts always exhibit superior catalytic properties in the oxidation of cyclohexene and styrene by molecular oxygen at atmospheric pressure, compared with the pyrrolidone-free SBA-15 supported Au catalyst (Au/SBA-15-N). This phenomenon is reasonably related to the interaction between Au nanoparticles with Py species, which is consistent with results analyzed from our density-functional theory (DFT) calculations.