Tandem Catalysis for Simultaneous Removal of NOx and C3H8 with Inhibition of N2O

Tandem catalysis is widely adopted for multipollutant control in mobile sources but has rarely been reported in stationary source emission elimination. This work proposed a tandem arrangement way with up-streamed V 2 O 5 /TiO 2 + down-streamed Cr 2 O 3 /TiO 2 catalysts, which could achieve the efficient synergistic control of NO x and C 3 H 8 in industrial flue gas. Moreover, this arrangement successfully alleviated the unwanted N 2 O formation during the NH 3 -SCR process. Compared to the conventional impregnation method of the Cr 2 O 3 –V 2 O 5 /TiO 2 catalyst, the tandem catalysts of V 2 O 5 /TiO 2 + Cr 2 O 3 /TiO 2 could enhance the NO x and C 3 H 8 conversion by 4.2% and 39.5%, respectively, at 350 °C. It might be attributed to the fact that Cr species was the active site for C 3 H 8 oxidation, and the tandem arrangement of catalysts was beneficial to even dispersion of active components on supports. Furthermore, due to the preferential NO x removal over the up-streamed V 2 O 5 /TiO 2 catalyst, the tandem catalysts obviously alleviated the N 2 O formation caused by Cr species during the NH 3 -SCR process. Herein, it significantly decreased N 2 O formation by 240.5% at 350 °C compared to the Cr 2 O 3 –V 2 O 5 /TiO 2 catalyst, achieving multipollutant emission control from industrial flue gas with the performance of “one stone three birds”.