Selective catalytic reduction using controlled catalytic deactivation

摘要

An exhaust treatment control system includes a controller configured to determine a value representative of a NO2 concentration associated with an exhaust gas upstream of a selective catalytic reduction (SCR) catalyst, and determine a value representative of a NO concentration associated with the exhaust gas upstream of the SCR catalyst. The controller can also be configured to transmit a signal to at least partially control an injection of a hydrocarbon into the exhaust gas, wherein the hydrocarbon injection can occur upstream of an oxidation catalyst to at least partially decrease the NO2 concentration of the exhaust gas downstream of the oxidation catalyst, and wherein the oxidation catalyst can be located upstream of the SCR catalyst.