Topic
MCM-41
About: MCM-41 is a research topic. Over the lifetime, 2355 publications have been published within this topic receiving 91416 citations.
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TL;DR: The mesoporosity of the particles turns out to be very important for effective proton transport since non-porous silica nanoparticles exhibit worse efficient proton Transport, and the obtained particle size dependence might open up a new route in rational design of highly proton conductive materials.
Abstract: Nanometer-sized mesoporous silica particles of around 100-nm diameter functionalized with a large amount of sulfonic acid groups are prepared using a simple and fast in situ co-condensation procedure. A highly ordered hexagonal pore structure is established by applying a pre-hydrolysis step in a high-dilution synthesis approach, followed by adding the functionalization agent to the reaction mixture. The high-dilution approach is advantageous for the in situ functionalization since no secondary reagents for an effective particle and framework formation are needed. Structural data are determined via electron microscopy, nitrogen adsorption, and X-ray diffraction, proton conductivity values of the functionalized samples are measured via impedance spectroscopy. The obtained mesoporous SO(3)H-MCM-41 nanoparticles demonstrate superior proton conductivity than their equally loaded micrometer-sized counterparts, up to 5 x 10(-2) S cm(-1). The mesoporosity of the particles turns out to be very important for effective proton transport since non-porous silica nanoparticles exhibit worse efficient proton transport, and the obtained particle size dependence might open up a new route in rational design of highly proton conductive materials.
53 citations
TL;DR: Chromium-containing mesoporous MCM41 and MCM-48 silicate molecular sieves were synthesized and characterized in this article, showing significant activity for the chosen (ethylbenzene oxidation) reaction even after several recycling or washing treatments.
Abstract: Chromium-containing mesoporous MCM-41 and MCM-48 silicate molecular sieves were synthesized and characterized. Unlike the chromium-containing microporous materials, the mesoporous analogues show significant activity for the chosen (ethylbenzene oxidation) reaction even after several recycling or washing treatments.
53 citations
TL;DR: Mesoporous silicas of MCM-41 type modified by transition metal oxides, such as molybdenum, vanadium, and tungsten, were synthesized as discussed by the authors.
Abstract: Mesoporous silicas of MCM-41 type modified by transition metal oxides, such as molybdenum, vanadium, and tungsten, were synthesized These materials were characterized by low-temperature nitrogen adsorption/desorption, Fourier transform infrared spectroscopy, X-ray spectral fluorescence analysis, and transmission electron microscopy techniques and applied for the removal of sulfur compounds in model and real fuels by oxidative desulfurization The catalysts obtained were tested under optimal conditions Dibenzothiophene was removed completely, and sulfur removal in gasoline and diesel fractions could reach 91 and 63%, respectively These catalysts retain their activity in gasoline fraction desulfurization for 5 cycles
53 citations
TL;DR: In this paper, a bismuth-containing MCM-41 was directly synthesized in strongly acidic media with CPBr as the template, and it was shown, for the first time, by ICP, XRD, N2 adsorption/desorption, TEM, SEM, 29Si MAS NMR spectra, UV-vis DRS, and Raman spectroscopy that all of the samples have high surface area and good crystallinity.
53 citations
TL;DR: In this article, the physicochemical properties of the materials have been investigated by means of XRD, N 2 adsorption/desorption, 27 Al MAS NMR and 29 SiMAS NMR, ESR, H 2 -TPR and FTIR combined with NO or NO+−NO 2 adaption.
53 citations