The Promoting Role of Noble metals on No_x Storage Catalyst and Mechanistic Study of NO_x Storage under Lean-Burn conditions

摘要

The promoting roles of noble metals (Pt, Rh, and Pd) and NO_x storage mechanism were investigated on alkaline earth metal oxide-based NO_x storage catalysts under lean-burn conditions. It was found that noble metals increased the reaction rates of NO oxidation to NO_2 an nitrite Oxidation to nitrate, resulting in an increase of NO_x adsorption and nitrate formation. The rates Of No oxidation to NO_2, nitrite oxidation to nitrate, and NO_x adsorption were found to increase In the order of CaO/Al_2O_3