نتایج جستجو برای: heterogeneous catalytic
تعداد نتایج: 202404 فیلتر نتایج به سال:
Heterogeneous catalytic hydrogenation of cyclohexene, catalyzed by Pt/A1203, was carried out in thirteenvarious solvents (four alcoholic solvents, six aprotic polar solvents and three non polar solvents) at 25 °C.Single-parameter correlations of logk vs. normalized polarity parameter (ETN), hydrogen-bond acceptorbasicity (p), hydrogen-bond donor acidity (a) and dipolarity/polarizibility (it*) d...
Catalytic wet air oxidation (CWAO) is one of the most economical and environmental-friendly advanced oxidation process. It makes a promising technology for the treatment of refractory organic pollutants in industrial wastewaters. Various heterogeneous catalysts including noble metals and metal oxides have been extensively studied to enhance the efficiency of CWAO. The present review is concerne...
A simple and mild one-pot three-component reaction for the preparation 1,4-dihydropyridines has been developed from various aldehyde substrates, 1,3-dicarbonyl compounds (dimedone) and ammonium acetate (Hantzsch method) in the presence of a catalytic amount of phospho sulfonic acid (PSA) as an efficient and heterogeneous solid acid in EtOH at room temperature. Preparation of PSA is straightforw...
In this paper, 4,4ʹ-bipyridinium dichloride supported SBA-15 (SBA@BiPy2+ 2Cl-) was used for the synthesis of dihydropyrimidinones. The synthesized catalyst was characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Thermogravimetric analysis (TGA). This nanocomposite was shown to be an efficient heterogeneous ca...
The low selectivity of heterogeneous catalysts has been one of the critical obstacles to the wider use of heterogeneous processes in the commercial production of high value chemicals. The limited selectivity is related to a number of issues, including the lack of predictive theories that guide the discovery of the optimal catalytic site, the dearth of strategies to synthesize the targeted sites...
A novel magnetically immobilized polyethyleneimine (PEI) fabricated by covalently anchoring on silica coated Fe3O4 nanoparticles (PEI@Si-MNPs) was prepared. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The immobili...
5-Substituted-1H-tetrazoles were synthesized by the [3 + 2] cycloaddition of sodium azide with various nitriles in the presence of nickel zirconium phosphate (NiZrP) as an effective heterogeneous catalyst in dimethylsulfoxide at 120 °C. This method has the advantages of good to high yields, simple methodology and easy work-up. The catalyst can be recovered by centrifuging and reused with good y...
A heterogeneous catalyst containing manganese Schiff base complex (derived from 2,4-dihydroxybenzadehyde and 1,2-phenylenediamine) is produced by covalent anchoring in MCM-41 matrix. The synthesized catalyst was characterized by X-ray diffraction pattern (XRD), inductivity coupled plasma (ICP), Fourier transform infrared (FT-IR) spectroscopy, N2 sorbtion-desorbtion isotherm and by tr...
Synthesis of indole derivatives was investigated and compared to the reaction of phenylhydrazine and ketones in the presence of the heterogeneous catalysts like kaolinite, montmorillonite K10 and Fe3O4 MNPs in ethanol under reflux conditions. After comparing the HPLC chromatogram of products it was compared and found that kaolin and montmorillonite K10 are better and more efficient candidate th...
Magnetic Cellulose/Fe3O4/Co3O4 nanocomposite as a new catalyst was synthesized and characterized by FT-IR, XRD, TGA, SEM, TEM, ICP-AES and VSM techniques. The catalytic activity of this heterogeneous catalyst was studied through one-pot synthesis of 1-((benzo[d]thiazol-2-ylamino)(aryl)-methyl)naphthalen-2-ol derivatives from three component reactions of aromatic aldehydes, 2-aminobenzothiazole,...
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