Mechanism of NO removal in selective catalytic reduction based on γ‐Fe₂O₃ catalyst doped with Mg element

Abstract The doping of different elements will make the Fe 2 O 3 catalyst show different catalytic characteristics and improve the activity of the Fe 2 O 3 catalyst in selective catalytic reduction (SCR), mainly by increasing the types of reactive oxygen species and the specific surface area of the catalyst. In this paper, density functional theory (DFT) was used to reveal the reaction path and adsorption behaviour of the Mg‐doped γ‐Fe 2 O 3 catalyst. The results show that the doping of Mg ions can contribute electrons and lead to electron migration on the catalyst surface, which changes the acidity of some sites on the catalyst surface. The adsorption energy of NH 3 is related to the binding sites of N atoms on the catalyst surface, and different adsorption sites will be enhanced or weakened due to Mg doping. NH 2 reacts with NO to form N 2 and H 2 O, so the dehydrogenation of NH 3 to the NH 2 radical is a key step in SCR. With doping, this process becomes more likely to occur. In addition, the activation energy barrier of NH 2 formation in the aerobic environment is lower than that in the anaerobic condition, which contributes to NH 3 dehydrogenation. Therefore, doping Mg on the surface of γ‐Fe 2 O 3 catalyst can improve the catalytic activity of NO removal.