Hierarchical structured Ti-doped CeO2 stabilized CoMn2O4 for enhancing the low-temperature NH3-SCR performance within highly H2O and SO2 resistance.

Developing effective and stable catalysts for low-temperature selective catalytic reduction (SCR) of NO x remains challenging. Herein, we constructed a hierarchical structure by loading CoMn 2 O 4 onto Ti-doped CeO 2 , that CoMn 2 O 4 /CeTiO x catalyst has shown superior deNO x activity (>95% at 100–225 °C), prominent reaction activation energy (28.8 ± 0.9 kJ mol−1) and outstanding stability (>75% at 100–200 °C within H 2 O and SO 2). The "low-temperature active sites" and "dual anti-poisoning sites" contribute to excellent activity and stability. Firstly, the hierarchical structure boosts generation of active metal-support interface, which is conducive to oxygen migration (including adsorbed oxygen (O ads), lattice oxygen (O lat) and oxygen vacancy (O v)) and metal charge transfer (Mn2+/3++Ce4+↔Mn3+/4++Ce3+, Ti4++Ce3+↔Ce4++Ti3+). This is the key to breaking through the limits of catalytic activity stability. Secondly, enhanced surface acidity favors NH 3 adsorption and activation, which accelerates -NH 2 /-NH concatenate with NO x through Eley-Rideal mechanism to generate N 2 and H 2 O. Thirdly, the dual strong SO 2 affinity sites by Ti-induced CeO 2 crystal reconstruction retard the active center affected by the sulfate species, which contributes to striking stability. This work highlights the importance of design of isolated active sites to improve SO 2 and H 2 O endurance. [Display omitted] • The CoMn 2 O 4 /CeTiOx catalyst exhibited excellent low-temperature SCR performance. • The CoMn 2 O 4 /CeTiOx catalyst took on a superior endurance to water and sulfur volatility at low-temperature. • The existence of cooperative interface of metal-support promotes electron cycling and reaction gas adsorption activation. • The supported catalysts were dominated by Eley-Rideal mechanism which was less effected by SO 2. • The presence of dual sacrifice sites delayed the deactivation of low-temperature active components. [ABSTRACT FROM AUTHOR]