نتایج جستجو برای: heterogeneous nano catalyst
تعداد نتایج: 215380 فیلتر نتایج به سال:
The growth of monoclinic Ga2O3 nanowires, nano-ribbons and nano-sheets has been investigated. Results indicate that high quality single crystal nanowires can be grown at 900°C using an Au catalyst, while single crystal nano-ribbons and nano-sheets require no metal catalyst for growth. Since bulk Ga2O3 is a promising material for high temperature sensing, Ga2O3 nanowires and nano-ribbons may pro...
We have prepared and characterized a SnO2-decorated Pt-Sn(oxidized)/C cathode catalyst in a polymer electrolyte fuel cell (PEFC). Oxygen reduction reaction (ORR) performance of Pt/C (TEC10E50E) remained almost unchanged or even tended to reduce in repeated I-V load cycles, whereas the I-V load performance of the Pt-Sn(oxidized)/C prepared by controlled oxidation of a Pt-Sn alloy/C sample with t...
In this study, Mn (III) salen complex was synthesized and immobilized onto the graphene oxide, which is modified by 3-chloropropyltrimethoxy silane. Heterogeneous catalyst was characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, fourier transform infrared spectra, nitrogen adsorption−desorption isotherm and atomic absorption spectroscopy. The catalyt...
Abstract Background The nano-sized particles enhance the exposed surface area of active part catalyst, thereby increasing contact between precursors and catalyst considerably. In this study, nano-SiO 2 /1,5-diazabicyclo[4.3.0]non-5-en was synthesized, characterized used as a heterogeneous nanocatalyst for synthesis tetrahydrobenzo[ b ]pyran derivatives. Fourier Transform Infrared Spectroscopy, ...
cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120 °c to afford 9,9-dimethyl-12-phenyl-8,10,11,12-tetrahydro-9-h-benzo[a]xanthen-11-one derivatives in high yields. also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under so...
synthesis of 2,4,5-triaryl-1h-imidazoles using a potent, green and reusable nano catalyst (fhs/sio2)
a simple, green and efficient method for synthesis of 2,4,5-trisubstituted imidazoles is described via three-component cyclocondensation of benzil or benzoin, aldehyde and ammonium acetate by using the nano sio2-supported ferric hydrogen sulfate (fhs/sio2), as a catalyst, under solvent-free conditions. the nano sio2 support and catalyst were characterized by x-ray diffraction (xrd), transmissio...
silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. all the compounds were characterized fully by ...
the aryl-(z)-n-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...
simple, cheap and green protocol for effective conversion of alcohols to corresponding carbonyl compounds in the presence of h14[nap5w30o110] and ammonium nitrate is reported. the products were characterized by ft-ir and comparison of their physical properties with those reported in the literatures. the progress of the reaction was monitored by thin layer chromatography (tlc) technique. the ali...
Artificial photosynthesis is a very attractive and a desirable way to solve the rising energy demand. In order to harvest energy directly from sunlight catalyst for oxygen reduction and evolution reaction are at the core of key renewable-energy technologies including fuel cells and water splitting. Herein, tungsten oxide-reduced graphene oxide (WO3-rGO), cobalt oxidereduced graphene oxide (Co3O...
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