Design of co-symbiotic FexMnyO catalysts for NO reduction by CO

Abstract

A smooth spherical Fe_xMn_yO catalyst with different Fe contents was prepared by the solvent thermal method using ethylene glycol and the CO-SCR activity of the catalyst was tested to deeply explore the influence of metal Fe doping amount on the activity of the manganese-based catalyst. It was found that the addition of Fe species resulted in a strong synergistic symbiosis between the two-phase composite oxides. For the optimized Fe_0.3Mn_0.7O catalyst at 300 °C, the NO conversion rate and N₂ selectivity reached 100% and 97.5%, respectively. The experimental results showed that the doping of FeO_x could promote the reaction Fe²⁺ + Mn⁴⁺ → Fe³⁺ + Mn³⁺, which was beneficial to the generation of oxygen cavitation and reactive oxygen species. Moreover, the unique smooth spherical morphology of MnO_x has a large specific surface area which fully provides the exposure opportunity for the active species FeO_x and improves the catalytic activity of the catalyst. In addition, according to the results of in situ infrared experiments, we propose a reasonable CO-SCR model reaction mechanism.