(342c) Mercury Oxidation over Cu-SSZ-13 Catalysts under Flue Gas Conditions
AIChE Annual Meeting
2017
2017 Annual Meeting
Catalysis and Reaction Engineering Division
Combustion Kinetics and Emissions II
Tuesday, October 31, 2017 - 1:14pm to 1:36pm
In this study, the activity of Cu-SSZ-13 was investigated for its ability to oxidize Hg under a variety of flue gas conditions. The Cu-SSZ-13 catalyst was compared to SSZ-13 to understand the effect of Cu in the Hg oxidation mechanism. The Hg oxidation performances of both zeolites were compared to that of a commercial SCR catalyst (V-Ti-W), which served as a benchmark. All catalysts required hydrogen chloride (HCl) to exhibit any Hg oxidation with the zeolites outperforming the commercial catalyst. However, the activity of all catalysts significantly decreased in the presence of either sulfur oxides (SOx) or SCR reactants (nitrogen oxide (NO)+ammonia (NH3)) in the flue gas, with SOx having a greater effect on Cu-SSZ-13 and SCR reactants having a greater one on the commercial catalyst. Additionally, it was determined that Cu was not the active site for Hg oxidation but was necessary for the SCR reaction. In fact, in the presence of SO2, Cu actually contributed to the deactivation of the catalyst for Hg oxidation, likely due to the formation of sulfates as confirmed by XPS analysis.