TY - JOUR AU - Békássy, Sándor AU - Cseri, T AU - Bodas, Z AU - Figueras, F TI - Investigation of montmorillonite-based clays in the preparation of supported ferric nitrate JF - NEW JOURNAL OF CHEMISTRY J2 - NEW J CHEM VL - 20 PY - 1996 IS - 3 SP - 357 EP - 364 PG - 8 SN - 1144-0546 UR - https://m2.mtmt.hu/api/publication/2649979 ID - 2649979 AB - A series of montmorillonite-based clays (KSF, KSF/0, K0, KP10, K10, KS from Sud-Chemie) were obtained by treating a Bavarian bentonite with different acids and a Hungarian bentonite (Mgd), and were used for the preparation of supported hydrated iron(III) nitrates. The clay supports were characterized by different methods (chemical analysis, nitrogen adsorption, X-ray powder diffraction, thermal analysis and solid-state NMR) and the acidity of these solids was determined by infrared spectroscopy using pyridine as a molecular probe. The supported iron nitrate reagents were investigated by thermal and X-ray powder diffraction methods. The iron nitrate is present on the support as an amorphous hydrate. The decomposition of the nitrate is shifted towards lower temperature when it is supported and starts at 35-40 degrees C. The supported iron nitrate reagents show high activities and selectivities in the oxidation of benzyl alcohol to benzaldehyde. The high specific surface area and the Bronsted acidity of the support are determining factors for the chemical activity of the supported system. The supported reagents prepared according this procedure can be stocked for as long as six months without any loss of chemical properties. LA - English DB - MTMT ER - TY - JOUR AU - CSERI, T AU - Békássy, Sándor AU - FIGUERAS, F AU - CSEKE, E AU - DEMENORVAL, LC AU - DUTARTRE, R TI - CHARACTERIZATION OF CLAY-BASED K-CATALYSTS AND THEIR APPLICATION IN FRIEDEL-CRAFTS ALKYLATION OF AROMATICS JF - APPLIED CATALYSIS A-GENERAL J2 - APPL CATAL A-GEN VL - 132 PY - 1995 IS - 1 SP - 141 EP - 155 PG - 15 SN - 0926-860X DO - 10.1016/0926-860X(95)00158-1 UR - https://m2.mtmt.hu/api/publication/2649981 ID - 2649981 N1 - Megjegyzés-23996503 PG: 15 AB - Toluene was alkylated with benzyl chloride and benzyl alcohol using a series of clays (KSF, KSF/0, K0, KP10, K10, KS from Sud Chemie) obtained by treating a bavarian bentonite by different acids and a Hungarian bentonite (Mad) as catalysts in a batch reactor. The catalysts were characterized by chemical analysis, thermal analysis, nitrogen adsorption, solid state nuclear magnetic resonance, X-ray diffraction. The acidity of these solids was determined by infrared spectroscopy using pyridine as molecular probe. The structure, specific surface area, and distribution of Lewis/Bronsted acidity of these clays can be changed to a great extent by acidic or thermal treatment. The rate of alkylation is related to Bronsted acidity when the substrate is benzyl alcohol. When benzyl chloride is used as alkylating agent, the Fe3+ content of the clay controls the activity, and iron containing clays show high activities in spite of their low Lewis acidities. LA - English DB - MTMT ER - TY - JOUR AU - Békássy, Sándor AU - Cseri, T AU - Kenessey, G AU - Pokol, György AU - Tomor, K AU - Liptay, György TI - Correlation between the reactivity and the structural and thermal properties of supported metal nitrates JF - JOURNAL OF THERMAL ANALYSIS J2 - J THERM ANAL VL - 40 PY - 1993 IS - 3 SP - 1285 EP - 1292 PG - 8 SN - 0368-4466 DO - 10.1007/BF02546892 UR - https://m2.mtmt.hu/api/publication/2609977 ID - 2609977 AB - Montmorillonite-supported iron(III) nitrate and copper(II) nitrate reagents, and other supported metal nitrates prepared in the same way, were investigated by thermal and X-ray powder diffraction methods. The metal nitrates are present on the support in the form of crystalline hydrate and not as acetone solvate as supposed earlier. Thermal decomposition of metal nitrates that are active in model reactions proceeds in a different way from that of the practically inactive nitrates. In the former case, water release and nitrate decomposition itself are simultaneous process. These and other results contributed to determination of suitable reaction conditions for the montmorillonite-supported reagents. LA - English DB - MTMT ER - TY - JOUR AU - Békássy, Sándor AU - CSERI, T TI - INVESTIGATION OF THE REACTIVITY OF METAL NITRATES ADSORBED TO MONTMORILLONITE JF - MAGYAR KÉMIAI FOLYÓIRAT (1895-1996) J2 - MAGY KÉM FOLY VL - 97 PY - 1991 IS - 8 SP - 339 EP - 343 PG - 5 SN - 0025-0155 UR - https://m2.mtmt.hu/api/publication/2649983 ID - 2649983 AB - The activity of montmorillonite-supported iron(III) nitrate and copper(II) nitrate was investigated in model oxidation and nitration reactions. It was established that, in contrast to literature data, even the less stable iron-reagent can be stored for weeks without substantial loss of activity. For complete oxidation of aromatic alcohols to carbonyl compounds there is no need for a significant excess of the reagents proposed in the literature. With an amount of iron-reagent less than the equivalent to the alcohol, the oxidation yield achieved was higher than proportional. This fact may place in doubt the adequacy of the accepted reaction mechanism. The rate of oxidation is markedly influenced by the nature of the solvent, the reaction is the fastest in benzene. The copper-reagent, which has not been used for this purpose before, is a good oxidant too. However, the oxidation yield with this reagent reaches that obtained with the iron reagent at a temperature by about 30-degrees-C higher. In the nitration of phenols the temperature could be increased to 60-degrees-C with the iron-reagent, so we have succeeded in reducing the reaction time to some hours. LA - Hungarian DB - MTMT ER -