Simultaneous removal of NO and Hg0 over Nb-Modified MnTiOx catalyst

Abstract Removal of NO and Hg 0 simultaneously was achieved on Nb-modified MnTiO x catalyst. Experimental results revealed that high NO conversion (>95%) and Hg 0 oxidation (>95%) in 200–300 °C were available on Mn 0.15 Nb 0.02 TiO x catalyst with a GHSV of 108,000 h −1 . The excellent catalytic performance of Mn 0.15 Nb 0.02 TiO x catalyst should be originated from its high reducibility and massive surface chemisorbed oxygen species. Moreover, the introduction of Nb into MnTiO x catalyst greatly enhanced its resistance to SO 2 and H 2 O. Neither gaseous Hg 0 nor HgO formed on catalyst surface could affect the NH 3 -SCR reaction. NO had a promotion effect on Hg 0 oxidation, while NH 3 was detrimental to Hg 0 oxidation owing to the inhibited adsorption of Hg 0 by NH 3 . Under SCR reaction conditions, an inhibition impact on Hg 0 oxidation could be detected, but this negative effect could be avoided by using more catalyst sample.