Mercury removal over Ce-doped LaCoO3 supported on CeO2 at low temperatures from coal combustion flue gas

Mercury has a significant impact on environment and is mainly derived from coal-fired power plant. Herein, we report a potential route for efficient removal of Hg0 via oxidation reactions using Ce-doped LaCoO3 supported on CeO2 catalyst. Catalyst characterization results proved that Ce can successfully substitute a desired part of Co into the LaCoO3 crystal lattice via a sol-gel method. The Hg0 removal experiments suggest that Hg0 removal effi-ciency decreased in the order of La0.875Ce0.125CoO3/CeO2 > La0.875Ce0.125CoO3 > LaCoO3. The presence of O2 provided more active oxygen and resulted in approaching 100% Hg0 removal efficiency. Introducing H2O and sole SO2 would significantly reduce the Hg0 removal efficiency as a result of competitive adsorption on the actives sites of the catalyst. On the other hand, SO2 could reacted with Hg0 in the presence of O2 and thereby recover the high Hg0 removal efficiency and the La0.875Ce0.125CoO3/CeO2 catalyst presented a good performance towards sulfur resistance. Furthermore, the catalyst still exhibited a high Hg0 removal efficiency performance after five times consecutive recycles.