Promotion effect of H2 pretreatment on CeO2 catalyst for NH3-SCR reaction

Abstract

In this study, the promotion effect of H2 pretreatment on the SCR performance of CeO2 catalyst was investigated based on the characterization results of XRD, H2-TPR, Raman and in situ DRIFT techniques. Lower crystallinity, higher reducibility and surface acidity can be found on CeO2-H catalyst. The results of DRIFT study reveal that the pretreatment of CeO2 catalyst with H2 can facilitate the adsorption of NH3 and NOx species, while the adsorbed NOx is basically inactive in the NH3-SCR reaction. Moreover, the reaction mechanism of the NH3-SCR reaction over CeO2 catalyst is not changed by H2 pretreatment, which is mainly under the control of Eley-Rideal (E-R) mechanism. The enhanced SCR performance of CeO2-H catalyst is mainly due to the promoted NH3 adsorption and the subsequent facilitation of SCR reaction through E-R pathway.