Abstract: Catalyst/catalyst support compositions are characterized by a supported cerium oxide, deposited onto a silica, alumina, titanium or zirconium based support, including particles of said supported oxide deposited onto said support, individualized or in the form of aggregates, no greater than 500 nm in size and having, after 6 hours of calcination at a temperature of at least 800° C., a measured reducibility from 30° C. and 900° C. of at least 80%; such compositions are prepared by combining a colloidal dispersion of the supported oxide and a suspension of the support, drying the resulting mixture by atomization and drying the resulting product by calcination.

Abstract: Catalyst/catalyst support compositions are characterized by a supported cerium oxide, deposited onto a silica, alumina, titanium or zirconium based support, including particles of said supported oxide deposited onto said support, individualized or in the form of aggregates, no greater than 500 nm in size and having, after 6 hours of calcination at a temperature of at least 800° C., a measured reducibility from 30° C. and 900° C. of at least 80%; such compositions are prepared by combining a colloidal dispersion of the supported oxide and a suspension of the support, drying the resulting mixture by atomization and drying the resulting product by calcination.

Abstract: Catalyst/catalyst support compositions are characterized by a supported cerium oxide, deposited onto a silica, alumina, titanium or zirconium based support, including particles of said supported oxide deposited onto said support, individualized or in the form of aggregates, no greater than 500 nm in size and having, after 6 hours of calcination at a temperature of at least 800° C., a measured reducibility from 30° C. and 900° C. of at least 80%; such compositions are prepared by combining a colloidal dispersion of the supported oxide and a suspension of the support, drying the resulting mixture by atomization and drying the resulting product by calcination.

Abstract: Colloidal dispersions of rare-earth borates include a liquid phase and borate colloids dispersed therein, these colloids having a mean hydrodynamic diameter of at most 200 nm and consisting essentially of elementary particles having a mean size of less than 100 nm; such dispersions are prepared by: (a) reacting a rare-earth oxide with a controlled amount of a water-soluble monovalent acid, having a pKa of from 2.5 to 5.0; (b) heating the medium thus obtained; (c) adding boric acid to the medium obtained and heating the resulting mixture; and (d) separating the solid product from the liquid medium thus obtained, and redispersing same in a liquid phase (the subject borates are useful luminophores, especially for the manufacture of luminescent transparent materials).

Abstract: The invention relates to a gold-based composition on a cerium oxide-based support having a halogen content with respect to a molar halogen/gold ratio equal to or less than 0.04, wherein the gold is embodied in the form of particles whose size is equal to or less than 10 nm. Said composition is made by a method consisting in bringing a cerium oxide-based compound into contact with a gold halide-based compound, thereby forming the suspension thereof, the thus obtained medium pH being fixed to a value of at least 8, subsequently, in separating a solid from a reaction medium and in washing said solid with a basic solution. The inventive composition can be used in the form of a catalyst in carbon monoxide oxidation methods, for treating tobacco smoke and air.

Abstract: The invention relates to a gold-based composition on a reducible oxide-based support characterised in that the halogen content thereof with respect to a molar halogen/gold ratio is equal to or less than 0.05, wherein the gold is embodied in the form of particles whose size is equal to or less than 10 nm and the composition is exposed to reduction treatment. The inventive composition can be used in the form of a catalyst in carbon monoxide oxidation methods, for treating tobacco smoke and air.

Abstract: The present invention concerns a composition based on a rare earth sulphide with improved stability, a process for its preparation and to use as a colouring pigment.