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

In this study, the promotion effect of H2pretreatment on the SCR performance of CeO2catalyst 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 CeO2catalyst with H2can facilitate the adsorption of NH3and NOxspecies, while the adsorbed NOxis basically inactive in the NH3-SCR reaction. Moreover, the reaction mechanism of the NH3-SCR reaction over CeO2catalyst is not changed by H2pretreatment,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 NH3adsorption and the subsequent facilitation of SCR reaction through E-R pathway.