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

Abstract In this study, the promotion effect of H 2 pretreatment on the SCR performance of CeO 2 catalyst was investigated based on the characterization results of XRD, H 2 -TPR, Raman and in situ DRIFT techniques. Lower crystallinity, higher reducibility and surface acidity can be found on CeO 2 -H catalyst. The results of DRIFT study reveal that the pretreatment of CeO 2 catalyst with H 2 can facilitate the adsorption of NH 3 and NO x species, while the adsorbed NO x is basically inactive in the NH 3 -SCR reaction. Moreover, the reaction mechanism of the NH 3 -SCR reaction over CeO 2 catalyst is not changed by H 2 pretreatment, which is mainly under the control of Eley-Rideal (E-R) mechanism. The enhanced SCR performance of CeO 2 -H catalyst is mainly due to the promoted NH 3 adsorption and the subsequent facilitation of SCR reaction through E-R pathway.