NO reduction by CO over a Fe-based catalyst in FCC regenerator conditions

A newly route for reduction of NOx by CO in the presence of an oxidization catalyst was proposed. In this strategy, O-2 is first consumed by CO in the presence of oxidized catalyst, and then NO in the deoxidized flue gas is reduced by CO in the presence of reduced catalyst. The catalytic performance of a Fe-based catalyst as an oxidization catalyst for the reduction of NO by CO under typical FCC regeneration conditions was investigated. In comparison with the FCC catalyst, the Fe-based catalyst enhances a rapid consumption of O-2 and improves the reduction of NO by CO even at lower temperatures. A kinetics model was proposed to describe the effect of O-2 concentration on the reduction of NO by CO. The reaction rate constant k increased with the temperature but decreased with the increase of O-2 concentration. The CO NO reaction will not occur until the O-2 concentration is below a threshold value, which would be attributed to the stronger adsorption ability of O-2 than NO. This newly developed approach is efficient and might be extended to the reduction of NO derived from coal combustion plant by precisely controlling the O-2 concentration. (C) 2014 Elsevier B.V. All rights reserved.