Modelling of Selective Catalytic Reduction of NO<sub>x</sub> with NH<sub>3</sub> over the Fe-Cu/ZSM-5 Catalyst

In this paper, a kinetic model was developed to simulate the reaction process of the Fe-Cu/zeolite Socony Mobil-5 (ZSM-5) catalyst for selective catalytic reduction of NO x with NH 3 (NH 3 -SCR).The global kinetic modeling accounted for various reactions occurring in SCR, including NH 3 adsorption/ desorption, standard SCR, fast SCR, slow SCR, NH 3 oxidation, NO oxidation and N 2 O formation reactions.The denitrification experiments were performed in a flow reactor with a feed stream, and the model could accurately predict the steady state conversion of NO at the reactor outlet.The results showed that the Fe-Cu/ZSM-5 catalyst exhibited an excellent catalytic activity, a high N 2 selectivity and an extended operating-temperature window across all temperatures ranging from 70 to 600ºC.By analyzing the influencing factors of the denitrification reaction, the results showed the temperature window shifted to lower temperatures with the gas hourly space velocity (GHSV), molar ratio of NH 3 /NO (normalized stoichiometric ratio, NSR), molar ratio of NO 2 /NO x as well as NO inlet concentration, and the operating window could be broadened with an increase in the O 2 concentration; lower GHSVs promoted the N 2 O formation.Due to ZSM-5 being rich in oxygen, the Fe-Cu/ZSM-5 catalyst exhibited high catalytic activity even without O 2 .The research findings could provide insight into improving low temperature SCR reactivity of zeolite-based catalysts.