MCM-41

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

Pd-functionalized MCM-41 nanoporous silica as an efficient and reusable catalyst for promoting organic reactions

Abstract: Pd-functionalized MCM-41 nanoporous silica has been explored as an efficient and recyclable catalyst to effect Suzuki and Mizoroki–Heck cross-coupling reactions, under various conditions. In Suzuki–Miyaura reactions, various aryl halides were coupled with aryl boronic acids at 100 °C under solvent-free conditions using K2CO3 as base and the maximum Ar–Ar yield reached 95%. The MCM(Pd)-41 catalyst was also used for a good range of Heck reactions using different aryl halides with styrene or n-butyl acrylate esters at 130 °C under solvent-free conditions using n-Pr3N as base that gave the maximum yields of 95% and 92%, respectively. High yield, low reaction times, non-toxicity and recyclability of the catalyst are the main merits of this protocol. The catalyst has been characterized by FT-IR, XRD, SEM, TEM, XPS, EDX, ICP-AES, TG and N2 adsorption–desorption.

Relationship Between the Pore Structure of Mesoporous Silica Supports and the Activity of Nickel Nanocatalysts in the CO2 Reforming of Methane

Abstract: The question remains over the role of the pore structure of the support material on the catalytic behaviour of Ni catalysts during the CO2/dry reforming of methane (DRM). For this reason, a series of mesoporous materials with different pore structures, namely MCM-41, KIT-6, tri-modal porous silica (TMS), SBA-15 and mesostructured cellular foams (MCFs) were synthesised via hydrothermal synthesis methods and further impregnated with 15 wt.% NiO (11.8 wt.% Ni). It was observed that synthesised TMS is a promising catalyst support for DRM as Ni/TMS gave the highest activity and stability among these materials as well as the Ni catalysts supported on classic ordered mesoporous silicates support reported in the literature at the relatively low temperature (700 °C). On the other hand, Ni supported on CMC-41 exhibited the lowest activity among them. To understand the reason for this difference, the physicochemical properties of these materials were characterised in detail. The results show that the thickness of the silica wall and the pore size of the support material play a critical role in the catalytic activity of Ni catalysts in the CO2 reforming of methane.

Preparation and characterization of functionalized Cu(II) Schiff base complex on mesoporous MCM-41 and its application as effective catalyst for the oxidation of sulfides and oxidative coupling of thiols

Abstract: An efficient and highly selective heterogeneous catalyst was prepared via immobilization of Cu(II) Schiff base complex on mesporous MCM-41. The Schiff base complex has been derived from 3,4-dihydroxybenzaldehyde and 3-amino propyl triethoxysilan, which is chemically anchored on the surface of MCM-41. Finally, resulting ligand was reacted with copper nitrate to produce Cu(II) Schiff base complex-MCM-41. Finally, resulting ligand was reacted with copper nitrate to produce Cu(II) Schiff base complex-MCM-41. The mesoporous catalyst has been characterized by fourier transform infrared spectroscopy, transmission electron microscopy, small angle X-ray diffraction, thermal gravimetric analysis, and N2 adsorption–desorption study. This heterogeneous catalyst showed excellent catalytic efficiency in the oxidation of various sulfides and thioles in the presence of urea hydrogen peroxide as oxidant and could be reused for at least 4 cycles without significant loss in activity.