نتایج جستجو برای: magnetic acid catalyst
تعداد نتایج: 1108805 فیلتر نتایج به سال:
A simple and efficient method for the chemoselective 1,1-diacetate protection of aromatic aldehydes with acetic anhydride by using Ni2+ supported on hydroxyapatite-core-shell magnetic γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp-Ni2+) under solvent free conditions. This method has several advantages, including high yield, short reaction time, simple work-up and recyclable property of the catalyst. The ca...
Nano silica sulfuric acid catalyzed synthesis of 2-substituted aryl (indolyl) kojic acid derivatives
Nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. The catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. The size of nanoparticles were observed with SEM.All prepared compounds w...
A series of arylidine barbituric acid derivatives was synthesized by Knoevenagel condensation reaction of aromatic aldehydes with barbituric acid or thiobarbituric acid using dodecylbenzenesulfonic acid as a Brønsted acid-surfactant catalyst in aqueous media. Regardless of the nature of the substitution (electron-donating and -withdrawing), all the reactions were completed within 15-65 min in w...
Alkanedisulfamic acid functionalized silica-coated magnetic nanoparticles (ADSA-MNPs) were used as effective, low-cost and reusable solid heterogeneous nanomagnetic catalysts for conversion of aldehydes and ketones to corresponding gem-dihydroperoxides and 1,2,4,5-tetraoxanes using aqueous hydrogen peroxide (30% w/w in H2O) at room temperature. These compounds are important ...
the catalytic oxidation of toluene to benzoic acid in the liquid phase has been studied in an un-stirred tank reactor. low concentration of acetic acid was added in order to increase the solubility of the catalyst in toluene. the dependence of the rate of reaction on the concentration of toluene catalyst and oxygen pressure was studied. it has been suggested that liquid phase oxidation of tolue...
Particulate Matter (PM) is one of the major harmful substances in diesel exhaust gas. Technologies like the Diesel Particulate Filter (DPF) and Diesel Oxidation Catalyst (DOC) have been positioned at the exhaust to reduce the quantity of harmful substances released to the environment. This paper highlights the factors that affect combustion in diesel engines and the potential of the introductio...
in this thesis, we exploit a simple and suitable method for immobilization of copper(ii) complex of 4?-phenyl-terpyridine on activated multi-walled carbon nanotubes [amwcnts-o-cu(ii)-phtpy]. this nanostructure was characterized by various physico-chemical techniques. to ensure the efficiency and fidelity of copper species, the implementation of three-component strategies in click-chemistry all...
A highly enantioselective hydrogenation of enamides catalyzed by a dual chiral-achiral acid system was developed. By employing a substoichiometric amount of a chiral phosphoric acid and acetic acid, catalyst loadings as low as 1 mol % of the chiral catalyst were sufficient to provide excellent yield and enantioselectivity of the reduction product.
BACKGROUND Solid acid catalyst was prepared from Kraft lignin by chemical activation with phosphoric acid, pyrolysis and sulfuric acid. This catalyst had high acid density as characterized by scanning electron microscope (SEM), energy-dispersive x-ray spectrometry (EDX) and Brunauer, Emmett, and Teller (BET) method analyses. It was further used to catalyze the esterification of oleic acid and o...
Magnetic bifunctional nanocatalyst supported on activated carbon (AC), CaO-Fe2O3/AC was synthesized via wet impregnation method and utilized for catalytic transesterification of waste cooking oil (WCO). A series characterization techniques were performed to determine acid-base properties, magnetism, thermal stability, crystallinity, chemical composition, surface morphology the catalyst. The BET...
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