Matumuene Joe Ndolomingo

TL;DR: In this article, the authors highlight the general features of supported M-NPs as catalysts with particular attention to copper, gold, platinum, palladium, ruthenium, silver, cobalt and nickel and their catalytic evaluation in various reactions.

TL;DR: It is shown that mesoporous metal oxides can be easily reduced at lower temperatures and that the immobilization of gold-palladium nanoalloy particles lowers their reduction temperatures.

TL;DR: In this paper, a kinetic study for the Cu and Au-catalyzed oxidation of benzyl alcohol to benzyldehyde was performed by tert-butyl hydroperoxide (TBHP) in the absence of any solvent using γ-Al 2 O 3 supported copper and gold nanoparticles.

TL;DR: In this paper, the kinetics of the catalytic oxidation of methylene blue, with hydrogen peroxide, were studied under mild conditions, and several copper catalysts were evaluated, with Cu/Li2O/γ-Al2O3 being the most active catalyst.

Abstract: We report on the kinetic analysis of catalytic activity of γ-Al 2 O 3 supported gold nanoparticles (AuNPs) on the rate of oxidation of morin by hydrogen peroxide as model reaction. Gold-based catalysts were revealed to be very active in the oxidation of morin under mild conditions, especially when Li 2 O is used as additive, and cationic imidazolium ionic liquids are used as AuNPs stabilizer. All kinetic data could be modeled in terms of the Langmuir–Hinshelwood model; that is both reactants are assumed to be adsorbed on the surface of the nanoparticles. The apparent reaction rate could therefore be related to the surface of the nanoparticles, to the kinetics constant, related to the rate determining steps, and to the adsorption constant of the reactants. The organothiol adsorption-based technique for the determination of specific surface area and particle sizes of AuNPs on γ-Al 2 O 3 supports is also reported. A fair agreement was found between particle sizes obtained from ligand adsorption and TEM methods. Atomic absorption spectrometry (AAS), X-ray diffraction spectrometry (XRD), N 2 -physisorption (BET), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA) are used for the characterization of the catalysts, while the oxidation reaction and the ligand adsorption was followed by ultraviolet-visible spectrometry (UV–vis).