Direct NOx decomposition catalyst with improved activity and selectivity
AssigneeToyota Motor Engineering & Manufacturing North America, Inc.
InventorsKrishna Gunugunuri, Charles Alexander Roberts
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Abstract
A catalyst for direct decomposition of NO and NO2 to N2 and O2 has a CoFe2O4 spinel doped with potassium cations. The catalyst has high activity and good selectivity for N2 production, when potassium cations are loaded at a density of about 0.9 weight percent. Methods for making the catalyst include wet impregnation of a CoFe2O4 spinel with a solution of potassium cations, such as a KOH solution.
Claims12
A catalytic converter for the direct decomposition removal of NOx from an exhaust gas stream flowing at a temperature of from about 400° C. to about 650° C., the catalytic converter comprising:
- an inlet configured to receive the exhaust gas stream into an enclosure;
- an outlet configured to allow the exhaust gas stream to exit the enclosure;
- and
- a catalyst system contained inside the enclosure, the catalyst system comprising CoFe2O4 spinel in a nanoparticle form, having an average diameter of from about 2 nm to about 100 nm;
- and
- potassium cations doped in the spinel.
A method for direct decomposition removal of NOx from a gas mixture, the method comprising:
- exposing a gas mixture having NOx to a catalyst including a CoFe2O4 spinel doped with potassium cations at a loading density within a range of from about 0.5 to about 2.0 weight percent;
- and
- catalyzing a direct decomposition of the NOx to generate N2 without the presence of a reductant.
Dependencies are inferred from the claim text.