Patent ID: 6637197
Filing Date: 2003-10-28
Classification: B01D,F01N,F02D,G01N,Y02T

Abstract:
A method for selective rich/lean control of a combustion mixture for an operation of an NOx adsorption catalyst, comprising:storing NOx in a storage phase when the combustion mixture is set to be lean; converting the stored NOx in a regeneration phase when the combustion mixture is set to be rich; using an NOx concentration and an oxygen concentration in combustion exhaust gases in a flow direction behind the NOx adsorption catalyst for monitoring the storage phase and for monitoring the regeneration phase, respectively; determining the NOx concentration and the oxygen concentration by the same electrochemical gas sensor; and causing, using a measuring signal of the gas sensor, the storage phase to be initiated in response to a predetermined oxygen concentration not being attained, while a combustion mixture set to be rich is present.