Catalyst/catalyst support compositions comprising the oxides of zirconium, yttrium and tungsten
AssigneeRhodia Operations
InventorsOlivier Larcher, Emmanuel Rohart, Stephan Verdier, Guillaume Criniere, Deborah Harris, Heather Bradshaw
Life of this patent
Estimating the term…
Abstract
Compositions based on zirconium oxide, including 1 to 20% yttrium oxide, 1 to 30% tungsten oxide and the balance zirconium oxide, have a specific surface area of at least 40 m2/g after calcination at 700° C. for 4 hours and an acidity measured by the methylbutynol test of at least 90%, and are useful as catalyst or catalyst supports, especially for the treatment of motor vehicle exhaust gases.
Claims21
-13. (canceled)
A catalyst/catalyst support composition comprising zirconium oxide, yttrium oxide and tungsten oxide in the following proportions by mass:
- yttrium oxide:
- 1% to 20%;
- tungsten oxide:
- 1% to 30%;
- and
- the remainder being zirconium oxide.
Dependencies are inferred from the claim text.