Composition based on cerium, zirconium and tungsten, preparation process and use in catalysis
AssigneesRhodia Operations, Magnesium Elektron Limited
InventorsJulien Hernandez, Emmanuel Rohart, Rui Jorge Coelho Marques, Deborah Jane Harris, Clare Jones
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Abstract
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° 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.
Claims15
A composition comprising cerium, zirconium and tungsten, wherein the composition has the following mass contents, expressed as oxide:
- cerium oxide:
- from 5% to 30%;
- tungsten oxide:
- from 2% to 17%;
- the remainder as zirconium oxide;
- and in that after aging at 750° C. in an air atmosphere comprising 10% water, it has a two-phase crystallographic structure comprising a tetragonal zirconia phase and a monoclinic zirconia phase, with no presence of a crystalline phase comprising tungsten.
Dependencies are inferred from the claim text.