Cerium oxides, zirconium oxides, Ce/Zr mixed oxides and Ce/Zr solid solutions having improved thermal stability and oxygen storage capacity
AssigneeRhodia Rare Earths Inc.
InventorsJean-Pierre Cuif, Julie Lynn Shreeve Keyer, Steven Eric Deutsch
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Abstract
The production of cerium oxides, zirconium oxides, (Ce,Zr)O.sub.2 mixed oxides and (Ce,Zr)O.sub.2 solid solutions having improved particle size distribution, surface area, oxygen storage capacity and pore volume by the addition of an additive, such as anionic surfactants, nonionic surfactants, polyethylene glycols, carboxylic acids, and carboxylate salts, during the formation of the oxides or precursors thereof.
Claims35
A process comprising the reaction of a Metal salt solution selected from the group consisting of a cerium solution, a zirconium solution, a cerium and zirconium solution and mixtures thereof, a base, optionally an oxidizing agent and an additive selected from the group consisting of:
- a) anionic surfactants;
- b) nonionic surfactants
- c) polyethylene glycols;
- d) carboxylic acids;
- and
- e) carboxylate salts;
- to form a product.
A process comprising the step of washing or impregnating cerium hydroxides, cerium oxides, cerium hydroxy carbonates, cerium carbonates, zirconium hydroxides, zirconium oxides, zirconium hydroxy carbonates, zirconium carbonates, cerium/zirconium mixed hydroxides, cerium/zirconium mixed oxides, cerium/zirconium mixed hydroxy carbonates, cerium/zirconium mixed carbonates, cerium/zirconium hydroxide solid solutions, cerium/zirconium oxide solid solutions, cerium/zirconium hydroxy carbonate solid solutions cerium/zirconium carbonate solid solutions;
- and mixtures thereof with an additive selected from the group consisting of:
- anionic surfactants;
- carboxylic acids;
- carboxylate salts and mixtures thereof.
A process comprising the step of washing or impregnating cerium hydroxides, cerium oxides, cerium hydroxy carbonates, cerium carbonates, zirconium hydroxides, zirconium oxides, zirconium hydroxy carbonates, zirconium carbonates, cerium/zirconium mixed hydroxides, cerium/zirconium mixed oxides, cerium/zirconium mixed hydroxy carbonates, cerium/zirconium mixed carbonates, and mixtures thereof with an additive selected from the group consisting of anionic surfactants, carboxylic acids, carboxylic salts and mixtures thereof.
Dependencies are inferred from the claim text.