chemical vapor deposition was employed to synthesize carbon nanotubes with ni-loaded mcm-41 and mcm-48 as catalysts and acetylene as precursor at 750°c. mesoporous ni mcm-41 and ni mcm-48 molecular sieves were synthesized by a hydrothermal method and were characterized by xrd and n2 adsorption isotherm. the catalytically synthesized carbon materials were characterized with raman spectroscopy, n...

Önemli bir hammadde olan izobütene her geçen gün talebin artması, izobütan dehidrojenasyonunu dikkat çekici konuma getirmiştir. Endotermik denge limitasyonlu bu reaksiyon için katalizör sentezi son derece önemlidir. Cr temelli katalizörler monokromatların en aktif tür olduğu bilinmektedir. Bu çalışmada, içeriğinin Cr@MCM-41 yapısına, kromat türleri ve miktarları üzerine etkilerinin araştırılmas...

The Ni-based catalyst has been intensively studied for CO methanation. Here, MCM-41 is selected as support to prepare xNi/MCM-41 catalysts with various Ni contents and the catalytic performance methanation in a slurry-bed reactor investigated under different reaction conditions. conversion gradually increases temperature or pressure rises. As content increases, specific surface area pore volume...

The influence of the chemical composition and silylation of mesoporous MCM-41 materials on the photochromic behaviour of adsorbed spiropyran (BIPS) and 6-nitrospiropyran was studied. Upon incorporation, the spiropyrans underwent ring opening to form either zwitterionic merocyanine or its corresponding O-protonated form. In all silica MCM-41 or in the MCM-41 containing aluminium, the O-protonate...

Molybdenum and zirconium mixed oxides were supported on siliceous MCM-41 mesoporous material. The resultant materials were characterized with various techniques such as X-ray diffraction (XRD), nitrogen adsorption, Transmission electron microscopy (TEM), XANES, NH3-TPD, and Diffuse reflectance infrared Fourier transform spectra (DRIFTS) of pyridine. It was found that the well-ordered channeling...

Methods of nonlocal density functional theory (NLDFT), proposed recently for predictions of adsorption equilibrium and calculations of pore size distributions in micro- and mesoporous materials, were tested on reference MCM-41 materials. Five newly synthesized MCM-41 adsorbents with presumably uniform pore channels varying from 32 to 45 Å were characterized by X-ray diffraction (XRD), nitrogen ...

The synthesis and characterization of new molecular sieves of the MCM-41 type are presented in this study. Samples were obtained from the alkoxides of Si, Ti and Al and different long-chain amine and alkylammonium salts surfactants, by the sol-gel method, through moderate agitation at room temperature. The reactions were conducted in two steps, acid hydrolysis (pH=2) and alkaline condensation (...

An efficient and economic approach is proposed for the fast and direct recovery of silica materials from photonic waste powder. Unlike the conventional alkaline fusion method for the extraction of silica from waste materials, this method possesses advantages of a rapid and low-energy-consumed process with total recovery yield. The obtained mesoporous silica material, denoted as MCM-41(DU)-F, wa...