Abstract: Compositions useful for treating the exhaust gases of diesel engines contain zirconium oxide, silicon oxide and at least one oxide of at least one element M selected from among titanium, aluminum, tungsten, molybdenum, cerium, iron, tin, zinc, and manganese, in the following mass proportions of these different elements: silicon oxide: 5%-30%; M-element oxide: 1%-20%; the balance being zirconium oxide; such compositions also have an acidity, as measured by the methylbutynol test, of at least 90% and are prepared by placing a zirconium compound, a silicon compound, at least one M-element compound and a basic compound in a liquid medium, thereby generating a precipitate, maturing the precipitate in a liquid medium and separating and calcining the precipitate.

Abstract: Compositions useful for treating exhaust gases contain zirconium, titanium and tungsten oxides, and optionally the oxide of an element M selected from among silicon, aluminum, iron, molybdenum, manganese, zinc, tin, and rare earths in the following mass proportions of these different elements: titanium oxide: 20%-50%; tungsten oxide: 1%-20%, M-element oxide: 1%-20%; the balance being zirconium oxide; such compositions are prepared by placing in a liquid medium a zirconium compound, a titanium compound, optionally an M-element compound and a basic compound, adding a tungsten compound to the precipitate suspension thus obtained and having a pH value ranging from 1 to 7, maturing the suspension resulting from the preceding step, and optionally separating the precipitate and calcining same.

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 composition essentially consist of oxides of zirconium, cerium and lanthanum and of another rare earth selected from among yttrium, gadolinium and samarium, having a proportion of the lanthanum oxide and the oxide of the other rare earth of at least 15% and specific surfaces of at least 40 m2/g and at least 15 m2/g after calcination respectively for 4 hours at 1,000° C. and 10 hours at 1,150° C.; after calcination for 10 hours at 1,200° C. these have a surface of at least 7 m2/g and such surface is at least 5 m2/g for an embodiment in which after 10 hours of calcination at 1,150° C. the composition is in the form of a pure solid solution.

Abstract: Catalytic compositions useful, e.g., for the treatment of internal combustion engine exhaust gases, are based on zirconium oxide in a weight proportion of at least 25%, from 15% to 60% of cerium oxide, from 10% to 25% of yttrium oxide, from 2% to 10% of lanthanum oxide and from 2% to 15% of another rare earth oxide, have a specific surface of at least 15 m2/g and a cubic phase, and are prepared from a mixture of zirconium, cerium, yttrium, lanthanum and the additional rare earth, by precipitating such mixture with a base, heating the precipitate in an aqueous medium, adding thereto a surfactant and calcining the precipitate.

Abstract: The processing of gases, in particular the exhaust gas of an internal combustion/diesel engine, entails catalytically oxidizing the carbon monoxide and hydrocarbons contained therein in an oxygen-rich medium, in the presence of a metal oxidation catalyst that includes a silica-containing zirconia support.

Abstract: Engines equipped with an exhaust line fitted with a particulate filter, in which the particulates contained in the exhaust gas are trapped on such filter, and wherein the trapped particulates are periodically burned off, are operated by improvedly catalyzing the combustion of said particles utilizing a composition containing mixture of a lubricating oil and a colloidal dispersion as the engine-lubricating composition, which dispersion includes particles of at least one compound of at least one rare earth and an amphiphilic agent.

Abstract: Catalyst compositions for the treatment of vehicular exhaust gases are based on zirconium and cerium oxides, have a cerium oxide content of at most 50% by weight, a level of reducibility of at least 95% after calcination in air at 600°, and a specific surface area after calcination for 4 hours at 1100° of at least 15 m2/g; such compositions are prepared by forming an aqueous mixture containing zirconium and cerium compounds, by heating this mixture to at least 100° and, after the heating, adjusting it to a basic pH, by adding a surfactant additive to the precipitate obtained from this mixture and by calcinating the precipitate in an inert gas or under vacuum at a temperature of at least 900° and then in an oxidizing atmosphere at a temperature of at least 600°.

Abstract: The invention concerns a composition based on zirconium oxide and cerium oxide and, optionally, an oxide of another rare earth, characterized in that it contains tin oxide in a proportion of more than 25 wt. % of oxide. Said composition is obtained by a method which consists in forming a mixture comprising zirconium, cerium and tin compounds and, optionally a compound of another rare earth; in bringing said mixture in the presence of a basic compound whereby a precipitate is obtained; heating said precipitate in an aqueous medium and calcining same. The composition can be used as catalyst, in particular for treating motor vehicle exhaust gases.

Abstract: Lubricant compositions contain a blend of a lubricating oil and a colloidal dispersion of particles of at least one iron compound and an amphiphilic agent; such compositions are useful for operating an engine, more particularly a diesel engine, which is equipped with an exhaust system fitted with a particle filter, wherein the particles present in the exhaust gases are trapped on the filter and, periodically, the trapped particles are burned, and further wherein the subject compositions are employed as engine lubricants with a view to catalyzing the combustion of the trapped particles.

Abstract: The invention relates to a method of producing a catalysed particulate filter. The invention is characterised in that, in order to lower the particulate oxidation temperature, the filter is provided with a cerium oxide, a zirconium oxide or a cerium/zirconium mixed oxide which can also comprise at least one rare earth oxide other than cerium. The porosity of said oxide or mixed oxide is such that at least 80% of the pore volume comprises pores having a diameter of least 20 nm.

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 invention relates to a process for forming a laminate comprising a core of a compressed metal powder mixed with a foaming agent between two metal layers, comprising the successive steps of providing two metal strips and a stock of powder comprising a metal powder mixed with a foaming agent; applying a layer of the powder between the two metal strips; feeding the metal strips, with the powder between them, to a rolling mill; rolling the two strips with the powder between them to form a laminate of compressed powder between two metal layers. The invention also relates to an associated device and to the product formed using the process.

Abstract: The invention relates to a process for forming a laminate comprising a core of a compressed metal powder mixed with a foaming agent between two metal layers, comprising the successive steps of providing two metal strips and a stock of powder comprising a metal powder mixed with a foaming agent; applying a layer of the powder between the two metal strips; feeding the metal strips, with the powder between them, to a rolling mill; rolling the two strips with the powder between them to form a laminate of compressed powder between two metal layers.