Promotional effect of aluminum doping on the sulfated Fe2O3 catalyst in selective catalytic reduction of NO with NH3

FemAlnOx catalysts were synthesized by the co-precipitation method and sulfated by (NH4)(2)SO4 impregnation method. Among the catalysts, 1.2S/Fe3Al1Ox exhibits NO conversion exceeding 90% in the range of 260-410 degrees C both in the catalytic activity and resistance to K poisoning testing. Structures and physicochemical properties of catalysts were measured via different characterization techniques. Through comparative studies between 1.2S/Fe2O3 and 1.2S/Fe3Al1Ox, it reveals that doping Al into Fe2O3 can reduce its particle size, increase its specific surface area, and suppress the formation of crystalline phase Fe-2(SO4)(3) at high calcination temperature, which is propitious to generate more surface sulfates in FemAlnOx. NH3-TPD and in-situ DRIFTS prove that K ions preferentially interact with surface sulfates, and more surface sulfates can provide more Br & oslash;nsted acid sites to obtain higher ability of resistance to K poisoning. This work provides a simple strategy to improve the catalytic performances of Fe-based catalysts.