SCR of NOx by NH3 over MnFeOx@TiO2 catalyst with a core-shell structure: The improved K resistance

Some fly ash components such as K could seriously weaken the catalytic performance of SCR catalyst. In this study, the core-shell-structured MnFeOx@TiO2 catalyst is synthesized by dipping deposition method and used for the NH3-SCR reaction. The results show that MnFeOx@TiO2 catalyst exhibits higher K resistance than MnFeOx/TiO2 catalyst prepared by impregnation method. And the correlativity between the core-shell morphology and K resistance of MnFeOx@TiO2 catalyst is studied by TEM, N-2 adsorption, XRD, XPS, TPR, TPD and in situ DRIFT It can be found that the shell of TiO2 has a protective effect on the active species in MnFeOx@TiO2 catalyst. And the core-shell structure of MnFeOx@TiO2 catalyst can produce more Mn4+ and chemisorbed oxygen species on its surface, improving reducibility and surface acidity. Moreover, the core-shell structure of MnFeOx@TiO2 catalyst is beneficial to the adsorption of NH3 and the formation of NO2, resulting in the favored SCR reaction via the Eley Rideal and the Langmuir Hinshelwood routes. Therefore, MnFeOx@TiO2 catalyst shows excellent K tolerance. (C) 2018 Energy Institute. Published by Elsevier Ltd. All rights reserved,