Rhodia Operations

Rhodia Chimie

Michelin Recherche Et Technique S.a.

Magnesium Elektron, Inc.

Compagnie Generale Des Etablissements Michelin

Cnrs

Julien Hernandez

Emmanuel Rohart

Rui Jorge Coelho Marques

Simon Ifrah

Olivier Larcher

Michael Lallemand

Clare Jones

Lionel Ventelon

Emmanuelle Allain

Deborah Jayne Harris

Rémi Valero

Lama Itani

Remi Valero

Laurent Guy

Virginie Harle

Damien Thomasson

Olivier Durel

Dominique Horbez

Arnaud Lapra

Fabien Ocampo

Lauriane D'Alencon

Mila Bortun

Catherine Enjalbert

Françoise Lafuma

Christophe Chassenieux

Marc Airiau

Deborah Jane Harris

Barry William Luke Southward

Christelle Perreur

Stéphane Denaire

Laure Bisson

Oguzhan Yaglidere

Rui Miguel Jorge Coelho Marques

Deborah Jayme Harris

Stephane Denaire

The present invention relates to a porous aluminum hydrate, to a process for preparing same and to the use of same as intermediate in the preparation of an alumina or of a mixed oxide based on aluminum, on cerium and on zirconium. The invention also relates to the alumina obtained from the aluminum hydrate.

Porous aluminum hydrate

The present invention relates to a mixed oxide of aluminium, of zirconium, of cerium, of lanthanum and optionally of at least one rare-earth metal other than cerium and lanthanum that makes it possible to prepare a catalyst that retains, after severe ageing, a good thermal stability and a good catalytic activity. The invention also relates to the process for preparing this mixed oxide and also to a process for treating exhaust gases from internal combustion engines using a catalyst prepared from this mixed oxide.

Mixed cerium- and zirconium-based oxide

The invention relates to a novel method of preparing silicas and to highly-structured silicas having the following characteristics: a specific surface area CTAB (S) of between 40 and 525 m/g; a specific surface area BET (S) of between 45 and 550 m/g; an object size distribution width Ld ((d84&#x2212;D16)/d50), which is measured by XDC particle size analysis after deagglomeration with ultrasound, of at least 0.91; and a pore-size distribution such that ratio V(d5&#x2212;d50)/V(d5&#x2212;d100) is at least 0.66. The invention also relates to the use of said silicas as polymer reinforcing fillers.

Method of preparing silicas, silicas with specific pore-size and/or particle-size distributions, and the uses thereof, in particular for reinforcing polymers

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

A dispersion includes an apolar organic phase, at least one amphiphilic agent, and solid objects based on particles of an iron compound in crystallized form of small size.

Organic dispersion of iron-based particles in crystallized form

The composition according to the invention includes a perovskite of the formula LaMO, where M is at least one element selected from among iron, aluminium or manganese, in the form of particles dispersed on an alumina or aluminium oxyhydroxide substrate, characterized in that after calcination at 700&#xb0; C. for 4 hours, the perovskite is in the form of a pure crystallographic phase, and in that the size of the perovskite particles does not exceed 15 nm. The composition according to the invention can be used in the field of catalysis.

Composition including a lanthanum perovskite on an alumina or aluminum oxyhydroxide substrate, preparation method and use in catalysis

Thermal and/or acoustic insulation materials based on dried precipitated silica, having a total pore volume of from 1 to 5 cm3/g and optionally containing reinforcing fillers and/or opacifying agents, are prepared by:

Thermal and/or acoustic insulation materials shaped from silica

Precipitated silicas including clusters of large primary silica particles having at the surface thereof small primary silica particles, have a specific surface area CTAB (S) ranging from 60 to 400 m/g; a cluster average size d50, as measured by XDC grading after ultrasound deagglomeration, such that d50 (nm)&#x3e;(6214/S(m/g)+23; a pore volume distribution such that V/V&#x3e;0.906&#x2212;(0.0013&#xd7;S(m/g)); and a pore size distribution such that Mode (nm)&#x3e;(4166/S(m/g))&#x2212;9.2; such silicas are useful reinforcing fillers for polymers.

Precipitated silica having particular morphology, grading and porosity, preparation thereof and reinforcing of polymers therewith

A diene rubber composition for tires based on at least (i) one diene elastomer, (ii) one reinforcing inorganic filler and (iii) one coupling agent which provides the bonding between the inorganic filler and the elastomer. The inorganic filler comprises at least one silica capable of being obtained by the preparation process of the type comprising the reaction of a silicate with an acidifying agent, whereby a silica suspension is obtained, followed by the separation and the drying of this suspension. The reaction of the silicate with the acidifying agent is carried out according to the following successive stages: (i) an aqueous suspension of precipitated silica, exhibiting a pH of between 2.5 and 5.3, is brought into contact (mixing) with acidifying agent and silicate, in such a way that the pH of the reaction medium is maintained between 2.5 and 5.3, (ii) silicate is added to the reaction medium obtained, so as to increase the pH of the reaction medium up to a value of between 4.7 and 6.3.

Diene rubber composition for tire including a silica as a reinforcing filler

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.

[object Object]

A composition is described that includes a perovskite of the formula LaMO, where M is at least one element selected from among iron, aluminum or manganese, in the form of particles dispersed on an alumina or aluminum oxyhydroxide substrate, wherein after calcination at 700&#xb0; C. for 4 hours, the perovskite is in the form of a pure crystallographic phase, and in that the size of the perovskite particles does not exceed 15 nm. The described composition can be used in the field of catalysis.

Composition including a lanthanum perovskite on an alumina or aluminium oxyhydroxide substrate, preparation method and use in catalysis

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

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 invention concerns a method for preparing anisotropic silica aggregates comprising the following steps: a) contacting at least one polymer with non-aggregated silica particles and/or highly dispersed in an aqueous medium, with a ratio R, polymer weight to silica particle surface, ranging between 0.03 and 2 mg/m; 2; and whereof the electrostatic value of the silica particle surface is not less than the value of the charge of the silica particle surface measured in an aqueous phase without added salts at a pH not less than 7; b) consolidating the aggregates obtained at step a) either by heat treatment, or by precipitation of a mineral compound. The invention also concerns a silica aggregate comprising a chaining of elementary particles whereof the number of particles ranges between 5 and 15, whereof 80% of elementary particles are in contact with not more than 2 particles and whereof the greatest distance measurable between 2 points of the aggregate is not more than 5 times the average size of one elementary particle.

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Antony, France

Julien Hernandez