Selective catalytic reduction of nitric oxide with ammonia in presence of oxygen over Mn-ZSM5

Abstract

Selective catalytic reduction of NO with NH₃in the presence of oxygen with and without humid conditions has been studied over Mn-ZSM5 and H-ZSM5. The Mn-ZSM5 has been prepared by wet impregnation method, characterized by X-ray diffraction technique, atomic absorption spectroscopy and BET surface area. Mn-ZSM5 shows better NO_x reduction than HZSM5. H-ZSM5 alone is a poor catalyst for NO_x reduction with NH_3, but metal incorporated catalyst becomes active. In the presence of humid condition Mn-ZSM5 gives lower NO₃ and NH₃ conversions. It may be concluded that the dispersed

manganese species are the active centres for the selective catalytic reduction of NO with NH₃ in the presence of oxygen.