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Vapor-phase synthesis of 2-methylpyrazine (2-MP), from propylene glycol (PG) and ethylenediamine (ED), has been studied over ferrite catalysts in a temperature range of 523-773 K. The performance of MnFe 2 O 4 was observed to be better than that of Zn 1-x Mn x Fe 2 O 4 (x ) 0, 0.25, 0.5, 0.75). The reaction was determined to be almost stoichiometric, with an ∼98% conversion of PG. A maximum yield of 80% of 2-MP could be obtained at a temperature of 723 K, using a feed of ED, PG, and water (ED:PG:H 2 O molar ratio of 1:1:2) over MnFe 2 O 4 . The influence of reactant molar ratio, reaction temperature, weight hourly space velocity (WHSV), and time on stream (TOS) on the product yield has been studied. Catalyst characterization was made using X-ray diffraction (XRD), surface area measurement and ammonia desorption methods, scanning electron microscopy that has been coupled with energy-dispersive X-ray analysis (SEM-EDX), and Mo ¨ssbauer spectroscopy. Increasing the manganese content in Zn 1-x Mn x Fe 2 O 4 (x ) 0, 0.25, 0.5, 0.75, and 1) increases the paramagnetism of the samples, which seems to be responsible for enhanced activity of the catalysts as the value of x increases from 0 to 1.0. A tentative mechanism for the reaction has been proposed. It has been concluded that, similar to chromites, ferrites also can function as a dehydration/dehydrogenation catalyst.

KEYWORDSZnO·Cr2O3 catalyst has been synthesized by low temperature, pH controlled co-precipitation route and characterized employing techniques of Brunauer, Emmett, and Teller (BET) surface area measurement, ammonia desorption technique, X-ray diffraction (XRD) and scanning electron microscopy (SEM). These characterizations reveal the catalyst to possess ZnO·ZnCr2O4 composition. The catalysts have been tested for their performance for the first time, in the synthesis of ethylene carbonate from cyclocondensation of ethylene glycol and urea. Effect of catalyst concentration, temperature and molar ratio of reactants has been studied to obtain the optimum conversion and selectivity of ethylene glycol and urea to ethylene carbonate. A maximum yield of 85.75% of ethylene carbonate was obtained at a temperature of 423 K and urea: ethylene glycol molar ratio of 1:1.5. A tentative mechanism of the reaction is proposed on the basis of analysis of reactants, products and modeling of the transition state for the reaction under density function theory using Gaussian09W software. Our studies suggest a consecutive mechanism for the reaction. In the first step, urea and ethylene glycol react to produce 2-hydroxyethyl carbamate, which undergoes further reaction to produce ethylene carbonate (EC) and ammonia. Urea Zinc chromite Ethylene glycol Co-precipitation Cyclocondensation Ethylene carbonate

A kinetic investigation of the slurry phase epoxidation of styrene with hydrogen peroxide has been carried out, for the first time, over nanoporous Au doped TS-1 catalyst, in a batch reactor, in the temperature range of 313-333 K. It was found that product selectivity and the rate of reaction are greatly influenced by concentrations of styrene and hydrogen peroxide. Kinetics studies reveal that the mechanism of the reaction is of the "Redox" type. The rate equation, r = k 1 k 2 P O P H / (k 1 P O + k 2 P H ) deduced, assuming a steady state involving two stage oxidation-reduction process, represent the data most satisfactorily for the conversion of styrene to styrene oxide. A tentative mechanism of the process has also been suggested.Keywords: Kinetics, Epoxidation, Au/TS-1, styrene, Styrene Oxide. SOLVENT-FREE PRESSURE-SENSITIVE ADHESIVESCatalytic epoxidation of olefins is an important issue from a practical as well as a mechanistic point of view. Epoxides as chemical intermediates find use in a wide variety of applications such as synthesis of several perfume materials, epoxy resins, plasticizers, drugs, sweeteners and other fine chemicals. Epoxidation of olefin compounds like styrene over titanium silicates molecular sieves; TS-1 (MFI) 1 -2 or TS-2 (MEL) 3 -4 using hydrogen peroxide 5 -7 and anhydrous urea-hydrogen peroxide 8 as oxidant has gained considerable interest.Metallic nanoparticles, finely dispersed onto high surface area supports are increasingly playing an important role in heterogeneous catalysis. In the liquid phase application, small gold particles (2 -7nm) deposited over different solid supports has received a growing interest as a catalyst for the selective oxidation of organic molecules 9 -10 . Direct epoxidation of propene using Au dispersed on TS-1 and other titanium containing supports has been reported by Nijhuis et al 11 .Although there are numerous publications on epoxidation of styrene 12 , to my knowledge, only two reports on the kinetics of the process over Au/TiO 2 and methyl rhenium trioxide catalysts have been found and no report on the kinetics of the process over Au-doped TS-1 was found. The present study was therefore undertaken to collect data on the rate of styrene oxide formation as a function of concentrations of reactants at various temperatures with a view to (1) finding a suitable model which could best explain the observed data and to (2) predicting the mechanism of the reaction. MATERIALS AND METHODSStyrene was procured from Aldrich, USA. Hydrogen peroxide and solvents like acetone, acetonitrile, methanol, carbon tetrachloride and isopropyl alcohol were procured from Merck. Tetrapropyl ammonium hydroxide, tetraethyl orthosilicate and tetrabutyl orthotitanate were also procured from Merck. Preparation of Gold Doped TS-1The catalyst was prepared as follows: To an aqueous solution of 25.25 g of Tetrapropyl ammonium hydroxide (TPAOH), 16.75 g of Tetraethyl orthosilicate (TEOS) was added slowly under vigorous stirring for 45 min in order to hydrolyze TEOS. A slight increas...