Scr catalysts with blended oxides and h-zeolites
OwnerYuejin LI, Xinyi WEI +1inventors
InventorsYuejin LI, Xinyi WEI, Andreas SUNDERMANN
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Abstract
Disclosed herein are catalyst compositions for treating an exhaust gas comprising nitrogen oxides (NOx) using ammonia or urea that comprise an oxide or mixed-oxide support optionally impregnated with a metal oxide dopant to form an oxide catalyst that is blended with an H-zeolite, or zeolite capable of being converted into an H-zeolite. The disclosure also relates to processes for making such catalyst compositions, and processes and methods for reducing NOx formation using the catalyst compositions and catalytic articles with the catalyst composition deposited thereon.
Claims15
A catalyst composition, for treating an exhaust gas comprising NOx using ammonia or urea, the catalyst composition comprising:
- an oxide or mixed-oxide support impregnated with a metal oxide dopant to form an oxide catalyst, and with an H-zeolite, or a zeolite capable of being converted to an H-zeolite.
A process of making a catalyst composition, the process comprising:
- (a) impregnating one or more oxide dopants onto an oxide or mixed-oxide support using an incipient wetness technique to form an oxide catalyst;
- (b) physically blending an H-zeolite, or zeolite capable of being converted into an H-zeolite, with the oxide catalyst in a slurry state to form a blend;
- and
- (c) calcining the blend at a temperature of at least about 450° C. for about 1 hour to obtain the catalyst composition.
A method for treating an exhaust gas comprising NOx, the method comprising contacting the exhaust gas with the catalytic article of claim 15 for a time and at a temperature ranging from about 200° C. to about 250° C. or higher, optionally for use in a heavy duty application positioned at a close-couple position.
Dependencies are inferred from the claim text.