• Bulletin of the Korean Chemical Society
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• v.30 no.10
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• pp.2249-2252
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• 2009

The clay-based Fe-bearing catalyst was successfully prepared through ion-exchange reaction and applied as heterogeneous catalyst for discoloration of acid fuchsine (AF) in an aqueous solution by Fenton-like reaction. Experimental results demonstrated that the AF discoloration ratios increased by increasing Fe-loaded clay dosage and initial $H_2O_2$ concentration, and by decreasing the pH, respectively. The lower the initial AF concentration, the shorter the reaction time needed to achieve complete discoloration of AF. Comparative studies indicated that AF discoloration ratios were much higher in presence of Fe-loaded clay and $H_2O_2$ than those in presence of $H_2O_2$, raw natural clay or Fe-loaded clay only and raw natural clay and $H_2O_2$ jointly. After AF discoloration, there existed no new phases in the clay samples detected by XRD and no change in the clay crystal morphology observed by SEM. A mechanism proposed suggested adsorption and Fenton-like reaction were responsible for discoloration of AF.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2724-2730
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• 2012

A new heterogeneous acidic catalyst was successfully prepared by impregnation of silica (Aerosil 300) by an acidic ionic liquid, named 1-(4-sulfonic acid)butylpyridinium hydrogen sulfate [$PYC_4SO_3H$][$HSO_4$], and characterized using FT-IR spectroscopy, the $N_2$ adsorption/desorption analysis (BET), thermal analysis (TG/DTG), and X-ray diffraction (XRD) techniques. The amount of loaded acidic ionic liquid on Aerosil 300 support was determined by acid-base titration. This new solid acidic supported heterogeneous catalyst exhibits excellent activity in the synthesis of 2-aryl-2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with aromatic aldehydes under solvent-free conditions and the desired products were obtained in very short reaction times with high yields. This catalyst has the advantages of an easy catalyst separation from the reaction medium and lower problems of corrosion. Recycling of the catalyst and avoidance of using harmful organic solvent are other advantages of this simple procedure.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2367-2374
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• 2013

Lysine (Lys) immobilized on zeolite 4A was prepared by a simple adsorption method. The physical and chemical properties of Lys/zeolite 4A were investigated by X-ray diffraction (XRD), FT-IR, Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis. The obtained organic-inorganic composite was effectively employed as a heterogeneous basic catalyst for synthesis of ${\alpha},{\beta}$-unsaturated carbonyl compounds. No by-product formation, high yields, short reaction times, mild reaction conditions, operational simplicity with reusability of the catalyst are the salient features of the present catalyst.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.2091-2092
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• 2011

• Journal of the Korean Chemical Society
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• v.62 no.6
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• pp.423-426
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• 2018

• Bulletin of the Korean Chemical Society
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• v.5 no.2
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• pp.79-82
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• 1984

This study concerns about catalyic cracking of iso-octane over cation ($Cd^{2+},\;Ca^{2+}\;and\;La^{3+}$) exchange mordenites. It deals with mordenite shape selectivity and with kinetics of this catalytic reaction. The striking feature was that over the region of cracking temperature investigated, 523-665K, the yield of isobutene was predominant, relative to that of larger or smaller carbon chain(s). This permits kinetic analysis of the heterogeneous catalytic system in terms of the modified pulse-version microcatalytic chromatography. The observed activation energy ($E_a,\;KJ\;mol^{-1}$) was found to be 46 for Cd-M, 57 for Ca-M and 59 for La-M, respectively.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3082-3084
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• 2009

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1119-1120
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• 2010

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.659-663
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• 2016

The efficiency of a heterogeneous ruthenium zirconia catalyst ($Ru(OH)_x/ZrO_2$) was demonstrated to the selective oxidative transformation of alkenes or alkynes. The scissions of C-C double bonds to aldehydes and triple bonds to diketones or carboxylic acids were carried out with (diacetoxyiodo)benzene as an oxidant under dichloromethane (5 mL)/water (0.5 mL) solvent system at $30^{\circ}C$ for wide range of substrates. The $Ru(OH)_x/ZrO_2$composite showed higher catalytic activity and selectivity than other ruthenium-based homogeneous or heterogeneous catalysts for the scission reaction. The catalyst exhibited a high mechanical stability, and no leaching of the metal was observed during the reaction. These features ensured the reusability of the catalyst for several times for the oxidative cleavage of unsaturated hydrocarbons.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.2099-2104
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• 2013

We present here an efficient and simple method for preparation of highly active Pd heterogeneous catalyst (CNT-Pd), specifically by reaction of dichlorobis(triphenylphosphine)palladium ($Pd(PPh_3)_2Cl_2$) with thiolated carbon nanotubes (CNTs). The as-prepared CNT-Pd catalysts demonstrated an excellent catalytic activity for the carbon-carbon (C-C) cross-coupling reactions (i.e. Suzuki, Stille, and decarboxylative coupling reactions) under mild conditions. The CNT-Pd catalyst could easily be removed from the reaction mixture; additionally, in the decarboxylative coupling of iodobenzene and phenylpropiolic acid, it showed a six-times recyclability, with no loss of activity. Moreover, once its activity had decreased by repeated recycling, it could easily be reactivated by the addition of phosphine ligands. The remarkable recyclability of the decarboxylative coupling reaction is attributable to the high degree of dispersion of Pd catalysts in CNTs. Aggregation of the Pd catalysts is inhibited by their strong adhesion to the thiolated CNTs during the chemical reactions, thereby permitting their recycling.