Catalyst for direct NOx decomposition and a method for making and using the catalyst
AssigneeToyota Motor Engineering & Manufacturing North America, Inc.
InventorsKrishna Gunugunuri, Charles A. Roberts, Torin C. Peck
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Abstract
Catalyst material comprising a ternary spinel mixed oxide for treatment of an exhaust gas stream via direct decomposition removal of NOx to N2 and O2. The low temperature (from about 400° C. to about 650° C.), direct decomposition is accomplished without the need of a reductant molecule. In one example, Mn may be incorporated into metal oxide, such as CuyCo3-yO4 spinel oxide, synthesized using co-precipitation techniques.
Claims14
A catalyst having activity for direct decomposition removal of NOx from an exhaust gas stream to N2 and O2, the catalyst comprising a material which comprises Mn-doped Cu—Co, wherein the Mn-doped Cu—Co comprises MnxCuyCo3.0-x-yO4, wherein 0.1<x≤0.3 and 0.1<y≤0.9, said catalyst having activity for direct decomposition removal of NOx at a temperature of about 500° C.
A method for direct decomposition removal of NOx from combustion engine exhaust, said method comprising:
- exposing an exhaust gas having NOx to a catalyst material which comprises Mn-doped Cu—Co having activity for direct decomposition to convert NOx to N2 and O2, wherein the Mn-doped Cu—Co comprises MnxCuyCo3.0-x-yO4, wherein 0.1<x≤0.3 and 0.1<y≤0.9, and wherein the direct decomposition removal of NOx is at a temperature of about 500° C.
A method of making a catalyst for removal of NOx from a combustion engine, the catalyst comprising a material which comprises Mn-doped Cu—Co, wherein the Mn-doped Cu—Co comprises MnxCuyCo3.0-x-yO4, wherein 0.1<x≤0.3 and 0.1<y≤0.9, said catalyst having activity for direct decomposition removal of NOx at a temperature of about 500° C., the method comprising:
- Co-precipitation using a precipitating agent selected from the group consisting of NaOH, Na2CO3, and (NH4)2CO3;
- drying the obtained precipitate;
- and
- calcining at 500° C. for a time period of from 1 hr to 5 hrs at a ramp rate of from 0.1° C./min. to 20° C./min.
A catalytic converter, comprising:
- a body defining a chamber, the body having an inlet to receive an exhaust gas stream into the chamber, and an outlet to allow the exhaust gas stream to exit the body;
- and
- a catalyst arranged in the chamber for direct decomposition removal of NOx from exhaust gas stream, the catalyst comprising a material which comprises Mn-doped Cu—Co having activity for direct decomposition to convert NOx to N2 and O2, wherein the Mn-doped Cu—Co comprises MnxCuyCo3.0-x-yO4, wherein 0.1<x≤0.3 and 0.1<y≤0.9.
Dependencies are inferred from the claim text.