Unveiling the evolution of N2O species over Atomically Dispersed Mn species supported on the TiO2 for NOx Selective Reduction with NH3 at we

Abstract Improving NH3 SCR catalytic performance of MnOx as well as suppress the N2O formation under wet condition are very crucial to better design Mn-based catalyst working in the real condition. Hence, we prepared atomic Mn speices supported on the TiO2 using impregnation method and tested in the NH3-SCR reaction both in dry and wet condition. We found that Mn species were highly dispersed on the TiO2 support from HAADF-STEM/EDX mapping. Based on our previous experiment results at the ESRF (A30-2-1160), this Mn single atom structure has been well confirmed, no Mn-Mn bond was observed from EXAFS. Mn single atom showed higher NO conversion, better water tolerance and less N2O formation. Besides, the N2O formation dramatically decreased under wet condition compared to dry condition. We speculated these could be closely related to different Mn sites’ local environment at wet SCR condition, which can be further confirmed with an operando XAS study.