Effect of oxygen on selective catalytic reduction of NO by NH3 over copper ion exchanged mordenite-type zeolite catalyst

Abstract

The effect of oxygen on the selective catalytic reduction of NO by NH3 was examined over a copper exchanged mordenite type zeolite catalyst. The catalytic activity for NO reduction by NH3 in the presence of oxygen was at least one order of magnitude higher than that in the absence of oxygen and it was fully reversible with respect to the presence of oxygen in the feed gas stream. Based upon ESR, TPD, TPO and TPSR studies, the redox behavior of copper ions was closely related to the enhancement of NO removal activity by the introduction of oxygen to the feed gases.