Low-temperature NH3-SCR catalytic characteristic of Ce-Fe solid solutions based on rare earth concentrate

Abstract

A variety of Ce-Fe solid solutions was synthesized by a microwave hydrothermal method following the molar ratio of Fe and Ce in Bayan Obo rare earth concentrate, to evaluate the catalytic action of Fe and Ce in NH3-SCR denitrification reaction. The microstructure, surface properties and catalytic activity of CeO2-Fe2O3/Al2O3 catalyst samples were characterized by NH3-SCR, SEM, BET, NH3-TPD, XRD, Raman, XPS, and DRIFTS. The results showed that the adsorption capacity of NH3 is the strongest when the molar ratio of Ce-Fe was 1:0.35, and the catalytic activity is the highest, up to 90%. The increase of iron species is beneficial to the denitration performance of the catalysts. The structure of CeO2 is distorted to form the Ce-Fe solid solutions, and more oxygen vacancies in the catalysts were exposed. Activated nitrate was generated from NO under the action of Ce3+and Fe2+, which was converted to N2 and H2O with the amide.