NOx Selective Catalytic Reduction over Pt Supported Catalyst Promoted by Zeolite and CeO2-ZrO2
نویسندگان
چکیده
The emission control of NOx in exhaust gases is one of the greatest engineering challenges to extend the practical and commercial application of diesel and lean burn engines. One solution is selective NOx reduction using hydrocarbons in an oxidizing atmosphere. We mainly focused on catalytic reactions under temperature excursion because of the resemblance to conditions prevailing in real automotive exhaust. Adsorbed hydrocarbon on zeolite was found to be highly effective in reducing NOx at elevating temperature. Thus, we proposed a novel catalyst formulation involving zeolite and CeO2-ZrO2. Our catalyst concept consists of supported Pt on thermally stable oxides (such as SiO2), zeolite and CeO2-ZrO2. Hydrocarbons adsorb on zeolite at low temperatures and migrate to the Pt surface at elevating temperature to reduce NOx. The active oxygen generated from CeO2-ZrO2 suppresses the poisoning effect of hydrocarbons at low temperature, promoting NOx reduction.
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