MCM-41

About: MCM-41 is a research topic. Over the lifetime, 2355 publications have been published within this topic receiving 91416 citations.

A facile method for promoting activities of vanadium–schiffbase complex anchored on organically modified MCM-41 in epoxidation reaction

Abstract: An organic–inorganic hybrid heterogeneous catalyst (V-MCM-41) was synthesized by anchoring vanadium–schiffbase complex on chloropropyl modified mesoporous silica (CP-MCM-41). Characterization of the functionalized ordered two-dimensional mesoporous material by powder X-ray diffraction (XRD), N2 adsorption–desorption, CP-MAS NMR spectroscopy (13C and 29Si), Fourier transform infrared spectroscopy (FT-IR), diffuse-reflectance UV–vis spectroscopy, demonstrate the successful grafting of vanadium complex into the functionalized mesoporous silica. It is also observed that the mesostructure has not been destroyed in multistep synthetic procedure. We have performed the epoxidation reaction of various olefins using V-MCM-41 as the catalyst, hydrogen peroxide as the oxidant and sodium bicarbonate as the co-catalyst in acetonitrile solvent. The co-catalyst enhances the rate of reaction by many folds. The reaction requires minimum amount of H2O2, short time period and most importantly occurs at room temperature. The heterogeneous catalyst can be recovered easily and reused many times without significant loss in catalytic activity and selectivity.

Pd(0)-Schiff-base@MCM-41 as high-efficient and reusable catalyst for C–C coupling reactions

Abstract: A Pd-Schiff-base grafted on functionalized mesoporous MCM-41 (Pd(0)-Schiff-base@MCM-41) was prepared using a post-grafting procedure and used as a highly efficient and reusable nanostructural catalyst for the carbon–carbon cross-coupling reactions of various aryl halides (including aryl iodide, bromide and chloride) with sodium tetraphenyl borate, phenylboronic acid and butyl acrylate. This catalyst exhibits interesting reactivity through Heck and Suzuki reactions.

Mesoporous materials from zeolite seeds as supports for nickel–tungsten sulfide active phases: Part 2. Catalytic properties for deep hydrodesulfurization reactions

Abstract: The properties of nickel–tungsten sulfide supported on MCM-41 aluminosilicate materials assembled from beta-zeolite seeds (β-MCM-41) were examined in the conversion of 4,6-dimethyldibenzothiophene (4,6-DMDBT) pure or in mixture with dimethyldisulfide, carbazole and tetralin. As reported in the part I, the properties of the acidic supports assembled from zeolite BEA seeds are strongly related to the preparation conditions, especially to the duration of the thermal treatment leading to the zeolite seeds. For this study, two materials were selected: one obtained after a short pre-treatment time ( t seeds = 6 h), whose structure is essentially MCM-41-like, and the other, obtained after a long pre-treatment time ( t seeds = 16 h) which is mostly zeolitic. In order to examine the effect of the acid function of the β-MCM-41 material on the catalytic properties of the supported catalyst, β-MCM-41-alumina supports were prepared by mixing the two oxides (0, 15, 50 and 85% β-MCM-41). The important and regular increase of activity observed upon increasing the β-MCM-41 content is due to an increase in the hydrogenation properties of the active phase, indicating an electronic effect of the acidity on the supported phase. It is particularly interesting to note that this advantage of the mesoporous support is maintained even in the presence of inhibitors. For zeolite-like support, the 4,6-DMDBT is also converted through isomerization.