High N(2) selectivity in selective catalytic reduction of NO with NH(3) over Mn/Ti–Zr catalysts

A series of Mn-based catalysts were prepared by a wet impregnation method for the selective catalytic reduction (SCR) of NO with NH(3). The Mn/Ti–Zr catalyst had more surface area, Lewis acid sites, and Mn(4+) on its surface, and showed excellent activity and high N(2) selectivity in a wide temperature range. NH(3) and NO oxidation was investigated to gain insight into NO reduction and N(2)O formation. The formation of N(2)O was primarily dominated by the reaction of NO with NH(3) in the presence of O(2)via 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.