Research on the catalytic oxidation of Hg0 by modified SCR catalysts

A series of metal oxides were employed to modify the commercial SCR catalyst, and the CeO2 modified SCR catalyst was selected and then subjected to detailed catalytic oxidation of Hg0 by using the simulated flue gas. The results indicated that the catalytic activity of the catalyst was increased remarkably after the CeO2 modification, and the highest catalytic oxidation of Hg0 was obtained from the modified SCR catalyst with 9% CeO2 loading, being 40% higher than that of the non-modified SCR catalyst. The BET and XRD analysis indicated that the surface area of the 1%–9% CeO2 modified SCR catalyst did not show significant changes as compared with the non-modified SCR catalyst, and the CeO2 was well dispersed on the catalyst surface without any aggregation. The flue gas condition had great effects on the Hg0 conversion. The catalytic oxidation of Hg0 would be significantly increased by HCl, and also increased as the increasing of the temperature in a certain range. The highest catalytic oxidation efficiency reached 95.11% at the optimal space velocity, temperature and flue gas components. In addition, the CeO2 doping did not affect the denitration efficiency of the SCR catalyst.