Passve regeneration：The DPF carrier is coated with a layer of precious metal catalyst. Under suitable temperature conditions, the NO2 produced by the DOC unit reacts chemically with the C in the DPF, and the chemical equation of the reaction is as follows
C+2NO2=CO2+2NO
C+O2=CO2
Main equations of chemical reactions for the removal of CO and HC in the DOC unit
4HC+5O２=2H2O+4CO
SQF+O2=H2O+CO
2CO+ O2 =2CO2
2NO+O2 =2NO2
C+O2=CO2
