Deactivation of mordenite-type zeolite catalyst by HCl for the reduction of NOx with NH3

Abstract The stability of mordenite-type zeolite catalyst by hydrochloric acid was examined to remove NO x contained in the flue gas from an industrial waste incinerator. Cu ion-exchanged mordenite (CuHM) catalyst was is easily deactivated under selective catalytic reduction reaction conditions when water and HCl simultaneously exist in the flue gas. The deactivation of CuHM catalyst is mainly caused by the evaporation of Cu ions from the framework of mordenite structure. To enhance the acidic tolerance of the catalyst, the Si/Al ratio of the catalyst was controlled and second metals were added to the catalyst. Such a modification significantly improved the deactivation of the catalyst by HCl, commonly contained in the flue gas from the industrial waste incinerator as well as NO.