Cold start NO2 generation system

A system comprising:

• a first electronic circuit configured to determine a portion of a three-way catalyst that corresponds to a first zone and a portion of the three-way catalyst that corresponds to a second zone, wherein the first zone corresponds to a hydrocarbon zone and the second zone corresponds to a nitrogen dioxide zone, and wherein the first zone is positioned before the second zone in the three way catalyst such that a fluid flowing through the three-way catalyst flows through the first zone before flowing through the second zone;
• a second electronic circuit configured to determine a temperature in the nitrogen dioxide zone;
• and
• a third electronic circuit configured to adjust an air/fuel ratio based on the temperature in the nitrogen dioxide zone.