Tandem Catalysis for Simultaneous Removal of NO and CH with Inhibition of NO.

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 VO/TiO + down-streamed CrO/TiO catalysts, which could achieve the efficient synergistic control of NO and CH in industrial flue gas. Moreover, this arrangement successfully alleviated the unwanted NO formation during the NH -SCR process. Compared to the conventional impregnation method of the CrO-VO/TiO catalyst, the tandem catalysts of VO/TiO + CrO/TiO could enhance the NO and CH 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 CH oxidation, and the tandem arrangement of catalysts was beneficial to even dispersion of active components on supports. Furthermore, due to the preferential NO removal over the up-streamed VO/TiO catalyst, the tandem catalysts obviously alleviated the NO formation caused by Cr species during the NH-SCR process. Herein, it significantly decreased NO formation by 240.5% at 350 °C compared to the CrO-VO/TiO catalyst, achieving multipollutant emission control from industrial flue gas with the performance of "one stone three birds".