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: A zirconium-based mixed oxide or zirconium-based mixed hydroxide which is capable of (a) at least 90% v/v conversion of naphthalene at atmospheric pressure at a temperature in the range 600-700° C. using a residence time of about 0.3 seconds, and/or (b) providing an initial heat of adsorption of ammonia of greater than 150 kJ/mol when measured by ammonia flowing gas microcalorimetry. Also, a method for purifying gas produced from the gasification of carbonaceous materials, comprising the step of bringing the gas into contact with such mixed oxides or mixed hydroxides.

Abstract: The present invention relates to oxygen storage components for catalytic converters for automobile exhaust systems, particularly for those with petrol-driven engines. In accordance with the present invention there is provided a ceria containing mixed oxide suitable as an oxygen storage material having a ceria content in the range 10 to 80% by weight and at least one metal oxide in an amount of less than 0.5% by weight, wherein the metal is selected from the first row transition elements and the group IVB elements of the periodic table. The inventions also provides an oxygen storage material for catalytic converters for automobile exhaust systems comprising an oxide of the present invention.

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 based on zirconium oxide, including 1 to 20% yttrium oxide, 1 to 30% tungsten oxide and the balance zirconium oxide, have a specific surface area of at least 40 m2/g after calcination at 700° C. for 4 hours and an acidity measured by the methylbutynol test of at least 90%, and are useful as catalyst or catalyst supports, especially for the treatment of motor vehicle exhaust gases.

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: 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: This invention relates to an improved amorphous zirconium hydroxide and a method for its production. The hydroxide has a surface area of at least 300 m2/g, a total pore volume of at least 0.70 cm3/g and an average pore size of between 5 nm and 15 nm, and is prepared by a process which comprises the steps of: a) preparing an aqueous solution comprising sulphate anions and a zirconium salt such that the ZrO2:SO3 ratio is 1:0.40 to 1:0.52, (b) chilling the solution to below 25° C., (c) adding an alkali in order to precipitate the amorphous zirconium hydroxide, (d) filtering and washing the precipitated zirconium hydroxide with water or an alkali to remove residual sulphate and chloride, (e) hydrothermally treating the zirconium hydroxide at a pressure of less than 3 barg, and (f) drying the zirconium hydroxide. The zirconium hydroxide of the present invention, which can be doped, is particularly useful in catalytic applications.

Abstract: The present invention relates to oxygen storage components for catalytic converters for automobile exhaust systems, particularly for those with petrol-driven engines. In accordance with the present invention there is provided a ceria containing mixed oxide suitable as an oxygen storage material having a ceria content in the range 10 to 80% by weight and at least one metal oxide in an amount of less than 0.5% by weight, wherein the metal is selected from the first row transition elements and the group IVB elements of the periodic table. The inventions also provides an oxygen storage material for catalytic converters for automobile exhaust systems comprising an oxide of the present invention.

Abstract: This invention relates to an improved amorphous zirconium hydroxide and a method for its production. The hydroxide has a surface area of at least 300 m2/g, a total pore volume of at least 0.70 cm3/g and an average pore size of between 5 nm and 15 nm, and is prepared by a process which comprises the steps of: a) preparing an aqueous solution comprising sulphate anions and a zirconium salt such that the ZrO2:SO3 ratio is 1:0.40 to 1:0.52, (b) chilling the solution to below 25° C., (c) adding an alkali in order to precipitate the amorphous zirconium hydroxide, (d) filtering and washing the precipitated zirconium hydroxide with water or an alkali to remove residual sulphate and chloride, (e) hydrothermally treating the zirconium hydroxide at a pressure of less than 3 barg, and (f) drying the zirconium hydroxide. The zirconium hydroxide of the present invention, which can be doped, is particularly useful in catalytic applications.