The promoting mechanism of doping Mn, Co, and Ce on gas adsorption property and anti-SO2 oxidation over γ-Fe2O3 (001) surface: A density functional theory study

Abstract To improve the deNOx and anti-poisoning performance of γ-Fe2O3 catalyst, the effects of three dopants Mn, Co, and Ce on gas adsorption and SO2 oxidation were investigated by a DFT method. Results show that NH3, NO, O2 can be adsorbed stably on the γ-Fe2O3 (001) surface to form coordinated NH3, nitrosyl, and adsorbed oxygen species, respectively. SO2 and H2O bind to Fe site on the catalyst surface by weak chemisorption. Doped Mn, Co, and Ce atoms simultaneously improve the gas adsorption performance of its own site and the surrounding Fe sites, especially for Ce doping. Furthermore, doping Mn contributes to the oxidation of SO2 to SO3, while doping Co and Ce restrains the formation of SO3, especially doping Ce, which is conducive to sulfur resistance of the catalyst. By comparison, the doping of Ce has more excellent deNOx and anti-poisoning property for the γ-Fe2O3 catalyst, which provides theoretical guidance for the selection of dopant in the subsequent experiments.