Potassium effect on the thermal stability and reactivity of NOx species adsorbed on Pt,Rh/La2O3 catalysts

▶ K decreases the noble metals capacity to decompose NOx species, especially for Pt. ▶ In the presence of Pt and/or Rh the trapped NOx are reduced at lower temperature. ▶ With catalysts containing K but no noble metals, the only reduction product is N2. ▶ The activity for soot combustion is improved by the presence of adsorbed nitrate species.