Abstract:
The invention relates to a catalyst for gas-phase oxidations, comprising an inert substrate and a catalytically active mass applied thereon, said mass containing vanadium oxide and titanium dioxide. The titanium dioxide has a content of sulfur compounds, calculated as S, of less than 1000 ppm and a content of calcium compounds, calculated as Ca, of less than 150 ppm. The catalyst has a higher activity and/or selectivity and thus enables higher yields of the desired target product, e.g., phthalic anhydride. The invention also relates to a method for producing phthalic anhydride, wherein a gas flow that contains molecular oxygen and o-xylene, naphthalene, or mixtures thereof, is brought into contact with the catalyst.
Abstract:
The invention relates to a method for producing nanoscale metal oxide-filled polymers. Said method is characterized by the following steps: a) producing a nanosuspension of one or more crystalline metal oxides, metal hydroxides or metal oxide hydroxides by heating a suspension of one or more compounds containing the corresponding metals in a first polymerizable compound to a temperature higher than the boiling point of water at process temperature and lower than the boiling temperature of the first polymerizable compound and also lower than the temperature at which polymerization of the first polymerizable compound begins, in the presence of water in an amount corresponding to 1 to 10 oxygen atoms per metal atom of the compound or of the compounds containing the corresponding metals, and b) polymerization of the first polymerizable compound under the conditions of temperature and pressure conventional for the first polymerizable compound.
Abstract:
The present invention relates to methods for the production of surface-modified, nanoparticulate particles of at least one metal oxide, metal hydroxide and/or metal oxyhydroxide and of aqueous suspensions of said particles. The invention also relates to the surface-modified, nanoparticulate particles of at least one metal oxide, metal hydroxide and/or metal oxyhydroxide and to the aqueous suspensions of said particles which can be obtained by these methods and their use for cosmetic sunscreen preparations, as stabilisers in plastics and as active antimicrobial active substance.