UNLABELLED BACKGROUND Structurally diverse aldehydes are successfully converted into acylals (1,1-diacetates) with acetic anhydride using NaHSO4-SiO2 as a mild, convenient and inexpensive catalyst under solvent-free conditions. The noteworthy features of the present system are shorter reaction times, and mild and solvent-free conditions. Furthermore, it offers chemoselective protection of al...

In recent years, information technology is growing rapidly, such as communication devices. However, there are still many shortcomings, for example, confidential information leaks caused by the leakage of electromagnetic waves used. A coating of electromagnetic materials or formation composite of electromagnetic material with other materials such as SiO2 is needed to overcome these problems. For...

Copper catalysts supported on silica or silica-alumina are used to promote the insertion of carbenes, coming from methyl phenyldiazoacetate and ethyl diazoacetate, into one C-H bond of THF, constituting the first example of this reaction promoted by a purely inorganic catalyst. Cu/SiO2-Al2O3 leads to better results, regarding yield and catalyst recovery, than with Cu/SiO2. With the former catal...

Increase in organic waste generation, dwindling nature of global oil reserves coupled with environmental challenges caused by waste oil disposal and burning of fossil fuels necessitated the need for alternative energy resources. Waste cooking oil obtained from the frying fish outlet was analyzed for its physicochemical properties using ASTM D-975 methods. Acid and Iodine values of the oil were ...

A highly efficient and general method for the synthesis of aryloylamido coumarinsderivatives by a three-component condensation of 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one, aryl glyoxals and benzamide in the presence of nano silica supported tin(II) chloride as a heterogeneous catalyst is established. In this method, SnCl2/nano SiO2 wasused as green and reusable catalyst. Excellent yie...

Cobalt talc doped with iron (Fe/Co~0.1) and dispersed in SiO2 aerogel was prepared from silica alcogel impregnated with metal nitrates by supercritical drying. Catalytic honeycombs were prepared following the same procedure, with the alcogel synthesized directly over cordierite honeycomb pieces. The composite aerogel catalyst was characterized by X-ray diffraction, scanning electron microscopy,...

Japan Several patterned growth techniques of single-walled carbon nanotubes (SWNTs) by modifing the dip-coating process are discussed. The conventional concept of using SiO2 patterned Si substrates to selectively grow 3D carbon nanotube structures can be applied to a dip-coating method followd by alcohol CVD growth. High-quality vertically aligned single-walled carbon nanotube (SWNT) patterns c...

A combination of a rotating gliding arc and spouted catalytic bed was investigated in plasma-catalytic system for dry reforming methane (DRM). Different nickel-based catalysts, including Ni supported on Al2O3 or SiO2 (fresh passivated) with 0, 15, 30 wt % Ni, were investigated. It found that more stable operation the obtained Al2O3-supported catalyst rather than catalyst. noticeable increase se...

Nano-silica supported boron trifluoride (BF3.SiO2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. So, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes  in good to excellent yields. The reactions were carried out at room temperature under solven...

in this article, the effect of operating conditions, such as temperature, gas hourly space velocity (ghsv), ch4/o2 ratio and diluents gas (mol% n2) on ethylene production by oxidative coupling of methane (ocm) in a fixed bed reactor at atmospheric pressure was studied over mn/na2wo4/sio2 catalyst. based on the properties of neural networks, an artificial neural network was used for model develo...