High N2 selectivity in selective catalytic reduction of NO with NH3 over Mn/Ti-Zr catalysts

Abstract

A series of Mn-based catalysts were prepared by a wet impregnation method for the selective catalytic reduction (SCR) of NO with NH3. The Mn/Ti-Zr catalyst had more surface area, Lewis acid sites, and Mn4+ on its surface, and showed excellent activity and high N2 selectivity in a wide temperature range. NH3 and NO oxidation was investigated to gain insight into NO reduction and N2O formation. The formation of N2O was primarily dominated by the reaction of NO with NH3 in the presence of O2via the Eley-Rideal mechanism. An intimate synergistic effect existed between the Mn-based and the Ti-Zr support. It was demonstrated that the Ti-Zr support greatly promoted the catalytic performance of Mn-based catalysts.