J. Petró

Enantioselective hydrogenation of acetophenone in the presence of S-proline

Abstract Enantioselective heterogeneous catalytic hydrogenation of acetophenone in the presence of S -proline was investigated. The effect of various catalytically active metals, reaction temperature and amount of catalyst on optical purity was studied. The correlation between optical yield and conversion, concentration of the reactants, different pretreatment methods and additives was also investigated.

Enantioselecttve hydrogenation of isophorone

Abstract The effects of catalyst, pH, hydrogen pressure and intensity of agitation in the enantioselective hydrogenation of isophorone were discussed. The changes in chemical and optical yield of the saturated ketone as functions of conversion and of the water content of the solvent have also been investigated. An iminium salt hydrogenation intermediate has been identified.

Magnetic studies of the adsorption on nickel catalyst

The effect of benzene and cyclohexane adsorption on the magnetization of industrial nickel catalyst has been studied, under the actual conditions of the hydrogenation of benzene in H2-argon mixtures of various partial pressures and in pure argon on previously dehydrogenated surfaces.AbstractВ действительных условиях гидрирования бензола исслед овалось на промышлен-ном никелевом катализаторе влияние адсорбции бензола и циклогексана на снижение намагниченности в смесях H2-аргона различных давлений, а также в аргоне, на предварительно дегидрированной поверхности.

Role of catalyst preparation and pretreatment in the stereoselective hydrogenation of thymol

Abstract The stereoselective hydrogenation of thymol was studied in the liquid phase with different palladium on carbon catalysts. Selcat catalysts in a basic medium were found to be the most selective for menthol formation. Their selectivity decreases, however, on pretreatment by hydrogen in water. Amines adsorbed on the catalyst surface are regarded to be responsible for this stereoselectivity.

An electrochemical measuring method for studies of metal catalysts in gas-phase heterogeneous catalytic reactions

Abstract An electrochemical measuring system has been developed for studying metal catalysts in contact with hydrogen and vapor-phase reactants at temperatures above 100 °C. The measuring system is a special galvanic cell in which the catalyst itself functions as measuring electrode. The electromotive force (emf) of this cell is continuously recorded in the course of catalyst activation and catalytic reactions. The system has been used for studying supported nickel, palladium, and platinum catalysts in tube reactors. Based on the presumed electrode processes taking place in the measuring cell, emf values measured with different catalysts and changes in the emf values taking place under the effect of various factors acting on the surface concentration of hydrogen (partial pressure of hydrogen, temperature, concentrations of reactants, catalyst poison, catalyst deactivation) have been interpreted.