The mechanism for NOx storage

The mechanisms for storing of NOx in platinum–barium–alumina catalysts during lean–rich transients are investigated. Oxidation of NO to NO2 is found to be an important step. NO2 is found to be important for oxidation of the catalyst or of nitrites to form nitrates. NOx is then stored in the form of surface nitrates. FTIR studies show no formation of bulk nitrates in these experiments.