Synergistic removal of NO and Hg0 over Co-Mn/TiO2 catalyst: High efficiency and in-depth reaction mechanism

The key challenge for controlling Hg 0 using selective catalytic reduction (SCR) technology is to develop a suitable catalyst capable of operating in a cost-effective manner, so it is necessary to study the in-depth reaction mechanism. Herein, Co-Mn/TiO 2 catalysts were fabricated by sol-gel method, excellent stability and high efficiency of Hg 0 removal (100%) and NO conversion (99%) are concurrently reached at 180 °C, which are benefited from the abundant active oxygen species on the catalysts. In order to clarify the synergistic reaction process, the mechanism of mutual effects between SCR atmosphere and Hg 0 is highly dedicated. Specifically, NO and O 2 were beneficial to Hg 0 oxidation, while NH 3 competitive adsorption with Hg 0 and consumption of active oxygen species prevent the Hg 0 oxidation. Impressively, the inhibition effect of NH 3 was not weakened but also intensified, mainly due to the co-existence of NO and NH 3 could induce partial HgO reduction. What's more, the direct evidence for the synergistic reaction mechanism of NO and Hg 0 is hypothesized by a combination of XPS and in-situ DRIFTs. These findings thus open up a way to address the simultaneous removal of NO and Hg 0 in industry. • The Co-Mn/TiO 2 catalysts exhibited superior performance for simultaneous removal of NO and Hg 0 . • The inhibition effect of NH 3 was not weakened but also intensified with the addition of NO. • The mutual effect between NO reduction and Hg 0 oxidation and synergistic reaction mechanism were systematically reviewed.