CATALYTIC CONVERTER [SKYACTIV-G 2.5T]

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Purpose, Function

•  The catalytic converter purifies contaminants in the exhaust gas by utilizing the chemical reactions of the three-way catalytic converter.
•  Exhaust gas is purified directly after engine start by the warm-up three-way catalyst (WU-TWC) and three-way catalyst (TWC).

Construction


WU-TWC

•  The catalytic converter (WU-TWC) is located on the engine side.
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TWC

•  The catalytic converter (TWC) is located behind the catalytic converter (WU-TWC).
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Operation

•  Contaminants in the exhaust gas (HC, CO, NOx) are purified by oxidization and reducing action while they are passing through the catalytic converter.
―  Oxidization process
•  Noxious hydrocarbon (HC) and carbon monoxide (CO) are bound with oxygen and converted to carbon dioxide and water.
O2+HC+CO→CO2+H2O
―  Reduction action
•  Noxious nitrogen oxide (NOx) is converted to non-noxious nitrogen and oxygen. A part of the oxygen generated in this process is used in the oxidization process.
NOx→N2+O2