Density functional theory study on catalytic reduction of NO on semi-coke containing N and Fe: The effect of CO

Abstract

NOx is a common air pollutant, and its removal research is imminent. In this paper, the semi-coke segment was used as the catalyst carrier to study the three important factors of nitrogen doping, iron doping and CO introduction, and the NO heterogeneous reduction was analyzed by the DFT calculation method. And at the range of 300 to 1000 K, the reaction kinetics was quantitatively analyzed by the conventional transition state theory (TST). Only one NO molecule was needed to finish the whole reaction path by doping the nitrogen, as suggested the nitrogen doping improved the NO removal rate at low NO concentrations. Through the analysis of the adsorption energy, it was found that the adsorption capacity of carbon active sites for NO and CO was significantly enhanced with iron doping. Among them, the appearance of FeO groups also reduced the activation energy of the stage reaction. In addition, the CO introduction significantly promoted the production of N2, CO2 and N2O, which was manifested in the reduction of activation energy of NO catalytic reaction and the increase of the N2 and N2O reaction rate constant. This theoretical research provided a theoretical foundation for the subsequent experimental research on NO removal.