C. S. Swamy

Methylation of pyridine over zeolites

Methylation of pyridine was carried out on H-Y, Na-Y, HZSM-5, Mordenite, ZSM-22, SAPO-5, MgAlPO-11 and Zeolite Beta. The major products formed in the gas phase reaction were 2-picoline, 3-picoline and/or 4-picoline along with other alkylated products in certain cases. From the results it was envisaged that the 2-picoline and 4-picoline may be obtained by the Ladenburg rearrangement via N-alkylation whereas the 3-picoline may be obtained by an initial hydrogenation route. The selectivity for the various products varied from one catalyst to the other thereby proving the complexity of the reaction mechanism due to the size and shape effects of the pores in the zeolite matrix.

Preparation and characterisation of cobalt containing layered double hypdroxides

Summary A series of hydrotalcites of general formula Co2+-M3+-CO3-HT (M3+=Al,Fe and Cr)are prepared by coprecipitation technique. The influence of parameters such as prepaaation method, atomic ratio, supersaturation levels, aging and texture of these treatments are investigated to study their effect on the structure and texture of these materials. The obtained materials scanning calorimetry, transmission electron microscopy and BET surface area measurements. Thermal calcination of these materials resulted in the formation of high surface area non-stoichiometric spinels whose catalytic acitivity is studied using N2O decomposition reaction as the test reaction. The order of activity observed is Co-Al-CO3-HT>Co-Fe-CO3-HT>Co-Cr-CO3-HT.

Studies on the catalytic decomposition of N2O over the solid solution La2CuxZn1−xO4 (0<X≤1.0)

Catalytic decomposition of N2O has been studied over a series of solid solution La2CuxZn1−xO4 (0<X≤1.0) at 200 Torr initial pressure of N2O, in the temperature range 330–490°C. The observed trends in the kinetics have been explained based on polaron hopping mechanism. Parallel variation between activity and magnetic susceptibility has been observed.AbstractКаталитическое разложение N2O исследовали на серии твердых растворов La2CuxZn1−xO4 (0<X≤1.0) при исходном давлении N2O 200 торр и при температурах 330–490°C. Наблюдаемые зависимости в кинетике объясняли на основе механизма перескакивания полярона. Наблюдали параллельное изменение в активности и магнитной восприимчивости.

Studies on the catalytic decomposition of N2O on rare earth nickelates

Decomposition of nitrous oxide has been studied on Ln2NiO4 (Ln=La, Nd or Pr) in the temperature range 380–460°C at 50 and 100 Torr initial pressures of the reactant gas. A multicenter adsorption model has been proposed to explain the observed kinetic behavior.AbstractРазложение закиси азота было исследовано на Ln2NiO4 (Ln=La, Nd или Pr) в интервале температуз 380–460°C и при давлении 50 и 100 торр реагирующего газа. Была предложена модель многоцентровой адсорбции для объяснения наблюдаемого кинетического поведения.

KINETICS OF THE ALKYLATION OF PHENOL WITH METHANOL OVER CATALYSTS DERIVED FROM HYDROTALCITE-LIKE ANIONIC CLAYS

Vapor phase alkylation of phenol with methanol was carried out over catalysts derived from a series of hydrotalcite (HT)-like compounds of the form M(II)Al-HT; where M(II)=Mg, Mn, Co, Ni, Cu and Zn with M(II)/Al atomic ratios of2–5. The kinetic parameters such as rate constant (k), apparent activation energy (Ea) and Arrhenius frequency factor (Ao) for the disappearance of phenol were evaluated employing a power law equation assuming pseudo-first order kinetics. The kinetic parameters were found to be in good agreement with phenol conversion. The existence of the compensation effect between Ea and ln Ao was tested.

Reaction of benzyl alcohol over the hydrogen storage intermetallic compound Mg2Cu

The reaction of benzyl alcohol over the hydrogen storage intermetallics Mg2Cu was studied in the temperature range of 573–773 K. Benzaldehyde and toluene, the major products, were produced by dehydrogenation and disproportionation reactions, respectively. Anthracene, stilbene and benzyltoluenes were also formed due to benzylation reaction. Since the benzylation course was strongly influenced by shape selectivity considerations, these were produced in minor amounts. Below 673 K, Mg2Cu behaves like metals while above 673 K it behaves like oxide systems in its catalytic properties.

Catalytic behavior of magnesium-copper intermetallic compound

Catalytic behavior of a magnesium-copper intermetallic alloy, Mg2Cu, in the hydrogenation of acetone has been studied in the temperature range of 393–423 K. A continuous flow type reaction was employed. Mg2Cu showed good catalytic activity with 2-propanol as the only product. A plausible mechanism for the mode of adsorption of acetone is proposed.

Catalytic decomposition of N2O on La2Cu0.5M0.5O4 (M=Co, Ni, Cu and Zn)

Decomposition of N2O has been studied over La2Cu0.5M0.5O4 (M=Co, Ni, Cu and Zn) between 380 and 485°C at 50 torr initial pressure of N2O to understand the mutual interaction of two different active metal ions of the same concentration and valence in deciding the physico-chemical and catalytic properties. A multicenter type of adsorption of N2O has been visualized and it is found that the rate is governed by the electronic factor.AbstractРазлоЗение N2O исследовали на катализаторах La2Cu0,5M0,5O4 (M=Co, Ni, Cu и Zn) в интервале температур 380–485°C и при исходном давлении N2O, равном 50 торр. Целью их было выяснение обоюдных взаимодействий двух различных активных металлических ионов одинаковой концентрации и валентности, определение физико-химических и каталитических свойств зтих соединений. Наглядно представлена мультицентровая адсорбция N2O. На скорость реакции влияет злектронный фактор.

Effect of rare earth ions on the catalytic activity of Ln2MnNiO6 perovskites

A series of rare earth transition metal perovskites has been synthesized and the catalytic activity tested for 2-propanol decomposition. The effect of rare earth ions on the catalytic activity can been understood from the correlations obtained between the physico-chemical properties and the catalytic activity of the perovskites.AbstractСинтезировали серию перовскитов, содержащих редкоземельные металлы, каталитическая активность которых была тестирована на разложении 2-пропанола. Эффект иона редкоземельного металла на каталитическую активность интерпретировал ся, исходя из зависимостей между физико-химическими свойствами и каталитической активностью перовскитов.

Oxidation of secondary alcohols byN-methylmorpholine-N-oxide (NMO) catalyzed by atrans-dioxo ruthenium(VI) complex or perruthenate complex: A kinetic study

Thetrans-dioxo ruthenium (VI) complex, [P(C6H5)3C6H5CH2]+[Ru(O)2OAcCl2] or tetrapropylammonium perruthenate catalyzes the oxidation of secondary alcohols to ketones byN-methylmorpholine-N-oxide (NMO). Kinetic studies showed the formation of a complex between catalyst and substrate (alcohol) as the first step in the mechanism.