Effect of shell layer thickness on low temperature SCR performance of FeMnOx@TiO2 core-shell catalysts

Abstract FeMnOx@TiO2 core-shell catalysts with different shell layer thicknesses were prepared by co-precipitation method to investigate the effect of shell layer thickness on the activity and stability of the catalyst for low-temperature denitrification. It was found that the NOx removal efficiency of FeMnOx@TiO2 with 60% (FM@T60) shell layer content was above 98% between 160 and 320 °C. The physicochemical properties of the catalysts were investigated and analyzed by characterization means such as XRD, BET XPS, H2-TPR. The TiO2 shell layer in FM@T60 effectively mitigated the toxic effect of SO2, provided a large specific surface and a concentrated pore size distribution facilitated the adsorption-desorption reaction of the catalyst. The large number of acidic sites in FM@T60 improved the NH3 adsorption performance. The abundant active components Mn3+, Fe3+ and a high proportion of chemisorbed oxygen of FM@T60 promoted the electron migration and conversion between the core-shell interface, which enhanced the redox capacity of the catalyst. The synergistic interaction between the core and shell of FM@T60 catalyst improved its low-temperature NH3-SCR reaction efficiency and sulfur resistance.