The enhancement of NH3-SCR performance for CeO2 catalyst by CO pretreatment

CO pretreatment was found to effectively improve the SCR performance of CeO2, with over 90% at about 300 degrees C. The larger specific area and the decrease of CeO2 crystallization indicated the modification of the surface structure after CO pretreatment. Abundant Ce3+ species and active oxygen, better reducibility, and the higher surface adsorption capacity were mainly responsible for its enhanced SCR performance. DRIFT analysis revealed the presumed coexistence of two reaction routes that the L-H mechanism was related to the reaction temperature, while the reaction rate of E-R route was almost directly proportional to the NO concentration at a certain temperature, based on the kinetic calculation. In addition, the CO-pretreated CeO2 also exhibited a better poisoning tolerance for SO2 and H2O and excellent thermal stability and circularity.