The study of NH3‐SCR mechanism on γFe2O3 supported LaMnO3 catalyst based on DFT

Abstract Fe 2 O 3 supported LaMnO 3 is an effective selective catalytic reduction (SCR) denitrification catalyst, but its reaction mechanism has not been reported yet. This article is based on the density functional theory (DFT) method to study the denitrification reaction mechanism of LaMnO 3 /Fe 2 O 3 catalyst, in order to guide the development and application of denitrification catalysts. The conclusion is as follows: NH 3 , NO, and O 2 molecules can form stable adsorption on the surface of La MnO 3 /γFe 2 O 3 catalysts, and NH 3 molecules are more likely to be adsorbed on Mn ions. Under the oxidation of lattice oxygen, NH 3 will gradually dehydrogenate to form NH 2 , and then will react with NO in the air to form the transitional intermediate NH 2 NO, to produce N 2 and H 2 O. The mechanisms are same on Mn and Fe sites. The dehydrogenate of NH 3 to form NH 2 is rate determining step. Compared with pure γFe 2 O 3 , the energy barrier decreases to promote the SCR process.