SCR of NOx with NH3 over Cu/NaZSM-5 and Cu/HZSM-5 in the presence of decane

The selective catalytic reduction of NOx with NH3 in the presence of decane over Cu/ZSM-5 catalysts prepared from H+ and Na+ZSM-5 precursors were investigated. Cu/NaZSM-5 catalyst showed significantly higher NOx conversion compared to Cu/HZSM-5. However, the presence of decane decreased the activity of both the catalysts, due to coke formation. Cu/HZSM-5 catalyst showed a larger decline in NOx conversion with time on stream compared to Cu/NaZSM-5. The higher activity of Cu/NaZSM-5 is attributed, to the promoting effect of Na+ cations in the formation of active Cu+ and nitrite and nitrate intermediates species and retardation of coke formation.