Abstract: Catalyst comprising a titania carrier and one or more metal compounds which metals are selected from the group consisting of vanadium, molybdenum and tungsten, which catalyst has a surface area measured by nitrogen adsorption of between about 70 m2/g and about 99 m2/g, a process for preparing such catalyst, catalyst obtainable by such preparation process and a process for selectively converting nitrogen oxide compounds with the help of such catalyst.

Abstract: An apparatus for performing physical and/or chemical operations is provided. The apparatus includes a holding means (3) provided with openings (2) for an array of reactor vessels (1); reactor vessels (1) positioned totally or partly within the openings (2), and connection means (5) capable of connecting the reactor vessels (1) and the holding means (3), which connection means (5) are located on or in the holding means (3) surrounding the openings (2) in which the reactor vessels (1) are positioned. Processes which can be carried out with the apparatus include, inter alia, mixing, cooling, heating, centrifugation, evaporation, filtration and pressure processes.

Abstract: A process for the preparation of an oxirane compound by reacting an olefinically unsaturated hydrocarbon with an organic hydroperoxide, in the presence of a catalyst comprising a titanasilsesquioxane of the general formula TiLR.sub.7 Si.sub.7 O.sub.12 and the structural formula ##STR1## wherein R is chosen from the group of cyclopentyl, cyclohexyl and cycloheptyl and L is chosen from the group of alkyl, cycloalkyl, alkylaryl, alkoxy, aryloxy, siloxy, amido and OH.