Rhodia Operations

Simon Ifrah

Olivier Larcher

Julien Hernandez

Emmanuel Rohart

Wei Zhang

Virginie Harle

Rui Jorge Coelho Marques

Rui Miguel Jorge Coelho Marques

Guillaume Criniere

Michael Lallemand

Stephan Verdier

Dominique Horbez

Thomas English

Andrew D Polli

Francis Francis

Lama Itani

Boris Chabert

Benjamin Faure

Ling Zhu

Laure Jeanne Simone Bisson

Stéphane Denaire

Oguzhan Yaglidere

Stephane Denaire

A mixed oxide, a catalytic composition, a catalytic wall-flow monolith, the use of the mixed oxide and the process of the preparation of the mixed oxide. The mixed oxide comprises zirconium, cerium, lanthanum and optionally at least one rare earth element other than cerium and other than lanthanum. The catalytic composition and the wall-flow monolith comprise the particles of the mixed oxide. The use of the mixed oxide is in the preparation of a coating on a filter. The process of preparation of the mixed oxide consists jet milling. The mixed oxide is a compromise between a calibrated size and a low viscosity when in the form of an aqueous slurry while retaining a high specific surface area and a high pore volume.

Mixed oxide based on cerium and zirconium

Disclosed are a mixed oxide composition based on zirconium and cerium exhibiting a high reducibility, the process for preparing it and its use in the field of catalysis.

Mixed oxide with improved reducibility

The invention relates to a mixed oxide composed of zirconium, cerium, lanthanum and at least one rare earth oxide other than cerium and lanthanum, having a specific porosity and a high specific surface area; to the method for preparing same and to the use thereof in catalysis.

Cerium- and zirconium-based mixed oxide

A composition including cerium and zirconium oxides, including at least 30 wt.-% cerium oxide is desired. Following calcination at a temperature of 900 DEG C. for 4 hours, the composition has two populations of pores, the diameters of the first population being centered around a value of between 5 nm and 15 nm for a composition including 30% to 65% cerium oxide or between 10 nm and 20 nm for more than 65% cerium oxide and the diameter of the second population being centered around a value of between 45 nm and 65 nm for 30% to 65% cerium oxide or between 60 nm and 100 nm for more than 65% cerium oxide.

Composition comprising cerium oxide and zirconium oxide having a specific porosity, preparation method thereof and use of same in catalysis

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

A composition of zirconium oxide and at least one oxide of a rare earth other than cerium is described. The zirconium oxide has a weight proportion of at least 50% and, after calcination at a temperature of 900&#xb0; C. for 4 hours, the composition exhibits two populations of pores of which their respective diameters are centered. The diameter of the first pore has a value of from 20 nm to 40 nm and in the second pore has a value of from 80 nm to 200 nm. Further described is how the composition can be used for treating the exhaust gases of internal combustion engines.

Composition based on zirconium oxide and on at least one oxide of a rare earth other than cerium, having a specific porosity, processes for preparing same and use thereof in catalysis

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

A porous inorganic composite oxide containing oxides of aluminum and of cerium and/or zirconium, and, optionally, oxides of one or more dopants selected from transition metals, rare earths, and mixtures thereof, and having a specific surface area, in m/g, after calcining at 1100&#xb0; C. for 5 hours, of &#x2267;0.8235[Al]+11.157 and a total pore volume, in cm/g, after calcining at 900&#xb0; C. for 2 hours, of &#x2267;0.0097[Al]+0.0647, wherein [Al] is the amount of oxides of aluminum, expressed as pbw AlOper 100 pbw of the composite oxide; a catalyst containing one or more noble metals dispersed on the porous inorganic composite oxide; and a method for making the porous inorganic composite oxide.

Porous inorganic composite oxide

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 composition is described that includes zirconium oxide, cerium oxide and yttrium oxide, or zirconium oxide, cerium oxide and at least two oxides of two rare earths different from cerium in a mass proportion of at least 20% of zirconium oxide and of at most 70% of cerium oxide, wherein the composition further includes, after calcination at 900&#xb0; C. for 4 hours, two populations of pores having respective diameters centered, for the first population, about a value of 20 nm to 40 nm and, for the second, about a value of 80 nm to 200 nm. The composition can be used for processing exhaust gases of internal combustion engines.

Composition containing oxides of zirconium, cerium and at least one other rare earth and having a specific porosity, method for preparing same and use thereof in catalysis

Catalyst compositions include finely divided nanoscale particles of at least one supported oxide selected from among zirconium oxide, titanium oxide or a mixed zirconium/titanium oxide deposited onto an alumina-based or aluminum-oxyhydroxide-based support, wherein, after calcination for 4 hours at 900&#xb0; C., the at least one support oxide is in the form of nanoscale particles deposited onto the support, the size of said particles being at most 10 nm when the at least one supported oxide is based is zirconium oxide and being at most 15 nm when the at least one supported oxide is titanium oxide or a mixed zirconium/titanium oxide; such catalyst compositions are especially useful for the selective reduction of NOx.

Catalyst compositions based on nanoparticles of a zirconium oxide, a titanium oxide or a mixed zirconium/titanium oxide deposited onto an alumina or aluminum oxyhydroxide support therefor

Catalyst compositions include finely divided nanoscale particles of at least one supported oxide, based on a zirconium oxide, a titanium oxide or a mixed zirconium/titanium oxide deposited onto a silica based support, wherein, after calcination for 4 hours at 900&#xb0; C., the supported oxide is in the form of nanoscale particles deposited onto the support, the size of the particles being at most 5 nm when the at least one supported oxide is based on a zirconium oxide, being at most 10 nm when the at least one supported oxide is based on a titanium oxide and being at most 8 nm when the at least one supported oxide is based on a mixed zirconium/titanium oxide; such catalyst compositions are especially useful for the selective reduction of NOx.

Catalyst compositions based on nanoparticles of a zirconium oxide, a titanium oxide or a mixed zirconium/titanium oxide deposited onto a silica support therefor

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

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La Jarrie, France

Simon Ifrah