Rhodia Operations

Rhodia Chimie

Magnesium Elektron, Inc.

Rhodia Electronics & Catalysis

Anan Kasei Co., Ltd.

Institut Regional Des Materiaux Avances

Rhodia Recherches Et Technologies

Emmanuel Rohart

Olivier Larcher

Julien Hernandez

Simon Ifrah

Stephan Verdier

Virginie Harle

Guillaume Criniere

Naotaka Ohtake

Rui Jorge Coelho Marques

Clare Jones

Deborah Jayne Harris

Aimin Huang

Bernard Pacaud

Dominique Horbez

Virginie Belliere-Baca

Kazuhiko Yokota

Christian Hamon

Claire Pitois

Eisaku Suda

David Monin

Mila Bortun

Heather Bradshaw

Lama Itani

Shigeru Aozasa

Toshihiro Sasaki

Deborah Jane Harris

Philippe Moissonnier

Laure Bisson

Stéphane Denaire

Hirofumi Takemori

Stéphan Verdier

Clive Butler

Lianxin Dai

Mairead Feeley

Rui Miguel Jorge Coelho Marques

Deborah Jayme Harris

Stephane Denaire

Jun Tokuda

Zirconium and yttrium oxide-based composition with a specific surface area of at least 12 m 2/g following calcination at 1000&#xb0; C. for 10 hours. This composition is obtained via a method wherein a mixture of zirconium and yttrium compounds is precipitated with a base; the resulting precipitate-containing medium is heated; a compound selected from anionic surfactants, non-ionic surfactants, polyethylene glycols, carboxylic acids and the salts thereof and carboxymethylated fatty alcohol ethoxylate-type surfactants is then added to said precipitate, and, finally, the precipitate is calcined. Said composition can be used as a catalyst.

Zirconium and yttrium-based composition, method for preparing same and use thereof in a catalyst system

The composition of the invention is based on oxides of cerium, of zirconium and of at least one rare earth metal other than cerium, with a cerium oxide content of greater than 50% by weight and it has, after calcination at 1000&#xb0; C. for 4 hours, a specific surface area of at least 20 m/g and an amount of mobile oxygen between 200&#xb0; C. and 400&#xb0; C. of at least 0.8 ml O/g. It is prepared by a process in which, in a reactor, a mixture of compounds of cerium, of zirconium and of the other rare earth metal is reacted continuously with a basic compound with a residence time of the reaction medium in the mixing zone of the reactor of at most 100 milliseconds; the precipitate is heated then brought into contact with a surfactant before being calcined.

Composition based on oxides of cerium, of zirconium and of another rare earth metal with high reducibility, preparation process and use in the field of catalysis

The invention relates to a composition containing zirconium, cerium and yttrium oxides with a cerium oxide proportion of between 3% and 15%, and yttrium oxide proportions corresponding to the following conditions: 6% at most if the cerium oxide proportion is between 12% excluded and 15% included; 10% at most if the cerium oxide proportion is between 7% excluded and 12% included; 30% at most if the cerium oxide proportion is between 3% and 7% included; the balance consisting of zirconium oxide. The composition may optionally include an oxide of a rare earth selected from lanthanum, neodymium and praseodymium. The composition can be used for processing the exhaust gases of a vehicle.

Composition containing zirconium, cerium and yttrium oxides having a high reducibility, method for preparing same and use thereof in catalysis

Thermally stable, solid alumina-based compositions useful for the trapping of nitrogen oxides that are contained in gaseous fluids, notably in vehicular exhaust gases, are formed of alumina, cerium and a divalent metal M selected from among barium, strontium or an association of these two elements and which include at least 10% of the weight of element M expressed by weight of oxide in contrast to the total weight of the composition and also wherein the aluminate compound of the metal element M, i.e., MAlO, is absent and not detectable by X-ray diffraction of the composition, after calcination thereof with air at 700&#xb0; C. for two hours.

Alumina-based nitrogen oxide (NOx) trapping compositions and treatment of vehicular exhaust gases therewith

The composition is based on zirconium oxide and at least one additive selected from zirconium oxide and at least one additive chosen from praseodymium, lanthanum or neodymium oxides, has a specific surface of at least 29 m 2/g after calcination at 1000&#xb0; C. during a period of 10 hours and is obtained by a method wherein a mixture of zirconium compounds and additive is precipitated with a base; the medium thus obtained, containing a precipitate, is heated and a compound chosen from anionic surfactants, non-ionic surfactants, polyethylene glycols, carboxylic acids and the salts thereof and surfactants such as the ethoxylates of caroboxymethyl fatty alcohols is added to the compound and the precipitate is calcinated; the composition can be used as a catalyst.

Composition based on zirconium oxides, praseodymium, lanthanum or neodymium, method for the preparation and use thereof in a catalytic system

A composition based on cerium, zirconium and tungsten is described. The composition has a content expressed as an oxide, of which cerium is from 5% to 30% of the composition, tungsten is from 2% to 17% of the composition, and the remainder of the composition is zirconium. After aging at 750&#xb0; C. under an air atmosphere including 10% water, it has a two-phase crystallographic structure having a tetragonal zirconia phase and a monoclinic zirconia phase, with no presence of a crystalline phase including tungsten. The composition can be used as a catalyst, especially in an SCR process.

Composition based on cerium, zirconium and tungsten, preparation process and use in catalysis

The invention relates to a method for treating a gas containing nitrogen oxides (NOx), in which an NOx-reduction reaction is carried out using a nitrogen-containing reducing agent, which invention is characterized in that the catalyst used for the reduction reaction is a catalytic system containing a composition comprising zirconium, cerium and niobium in the following percentages by weight, expressed in terms of the weight of oxide: 10-50% of cerium, 5-20% of niobium and the remainder consisting of zirconium.

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A method is described for treating a gas including nitrogen oxides (NO). The method can include conducting a reduction reaction of the nitrogen oxides with a nitrogen reducing agent. Further described, is a catalyst used for the reduction reaction which is a catalytic system including a composition based on cerium oxide and including niobium oxide in a proportion by a mass of from 2% to 20%.

Method for treating a gas containing nitrogen oxides (NOx), in which a composition comprising cerium oxide and niobium oxide is used as a catalyst

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 m/g and at least 15 m/g after calcination respectively for 4 hours at 1,000&#xb0; C. and 10 hours at 1,150&#xb0; C.; after calcination for 10 hours at 1,200&#xb0; C. these have a surface of at least 7 m/g and such surface is at least 5 m/g for an embodiment in which after 10 hours of calcination at 1,150&#xb0; C. the composition is in the form of a pure solid solution.

High specific surface/reducibility catalyst/catalyst support compositions comprising oxides of zirconium, cerium and lanthanum and of yttrium, gadolinium or samarium

A composition is described that includes oxides of zirconium, cerium and another rare earth different from cerium, having a cerium oxide content not exceeding 50 wt % and, after calcination at 1000&#xb0; C. for 6 hours, a maximal reducibility temperature not exceeding 500&#xb0; C. and a specific surface of at least 45 m/g. The composition can be prepared according to a method that includes continuously reacting a mixture that includes compounds of zirconium, cerium and another rare earth having a basic compound for a residence time not exceeding 100 milliseconds, wherein the precipitate is heated and contacted with a surfactant before calcination.

Composition containing oxides of zirconium, cerium and another rare earth having reduced maximum reducibility temperature, a process for preparation and use thereof in the field of catalysis

The inventive composition, according to a first embodiment, consists essentially of a cerium oxide and a zirconium oxide in an atomic ratio Ce/Zr of at least 1. According to a second embodiment, said composition is based on cerium oxide, zirconium oxide with an atomic ratio Ce/Zr of at least 1 and at least one rare earth oxide other than cerium. After calcination at 1100&#xb0; C., said composition has a specific surface of at least 9 m/g in the second embodiment. The inventive composition can be used as a catalyst especially for the treatment of waste gases from internal combustion engines.

Compositions based on cerium oxide, zirconium oxide and, optionally, another rare earth oxide, having a specific raised surface at 1100&#xb0; C, method for the production and use thereof as a catalyst

A method for decomposing NO is described. The method uses, as a catalyst, an oxide based on cerium and lanthanum, which further includes at least one oxide of an element chosen from zirconium and rare earths other than cerium and lanthanum. This catalyst is stable, enabling it to be used at high temperatures.

The inventive composition is based on cerium oxide and on zirconium oxide in an atomic proportion Ce/Zr of at least 1, and has a reducibility rate of at least 70% and a surface area of at least 15 m; 2; /g. This composition is obtained by a method in which: a mixture is made containing cerium and zirconium compounds; this mixture is provided with a basic compound whereby obtaining a precipitate that is heated in an aqueous medium; a surfactant-type additive or a polyethylene glycol or a carboxylic acid is added to this medium or to the separated precipitate; the mixture is ground; the precipitate obtained thereof is calcined under inert gas or vacuum, in a first period of time, at a temperature of at least 850 .iC and then under an oxidizing atmosphere, in a second period of time, at a temperature of at least 400&#xb0; C.

Composition based on cerium oxide and on zirconium oxide having a high reducibility and high specific surface, methods for the preparation thereof and use as a catalyst

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&#xb0;, and a specific surface area after calcination for 4 hours at 1100&#xb0; of at least 15 m/g; such compositions are prepared by forming an aqueous mixture containing zirconium and cerium compounds, by heating this mixture to at least 100&#xb0; 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&#xb0; and then in an oxidizing atmosphere at a temperature of at least 600&#xb0;.

Catalyst compositions for the treatment of vehicular exhaust gases comprise zirconium oxide and cerium oxide, and have a high reducibility and a stable specific surface area

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 m/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.

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Sainte Soulle, France

Emmanuel Rohart