Effects of exposed crystal facet on SO₂ resistance of -Fe₂O₃ for selective catalytic reduction of NO_x with NH₃

In this study, the effects of crystal facet on the NH3-SCR activity and SO2 resistance of a-Fe2O3 catalysts were investigated. Compared with Fe2O3(Slice) with (110) and (104) exposed and Fe2O3(Rod) with (110) and (012) exposed, Fe2O3(Cube) with only (012) facet exposed showed the worst fresh catalytic activity and SO2 resistance. The results of H-2-TPR, XPS, and in situ DRIFTS indicated that the lowest redox capacity resulted in the nonexistence of NOx activation on the surface of fresh Fe2O3(Cube). NH3-SCR on Fe2O3(Cube) could only be completed through the reaction between NOx and pre-adsorbed NH3 species. For Fe2O3(Slice), most Fe3+ was maintained, and the highest acid amount after SO2 treatment was helpful for its outstanding SO2 resistance. Considering the sequence of catalytic performance, designing a-Fe2O3 catalyst with (104) not (012) crystal facet exposed was helpful for improving the SO2 resistance of Fe2O3 catalysts. [Graphics] .