Role of Ceria in the Design of Composite Materials for Elemental Mercury Removal

The necessity to drastically act against mercury pollution has been emphatically addressed by the United Nations. Coal‐fired power plants contribute a great deal to the anthropogenic emissions; therefore, numerous sorbents/catalysts have been developed to remove elemental mercury (Hg0) from flue gases. Among them, ceria (CeO2) has attracted significant interest, due to its reversible Ce3+/Ce4+ redox pair, surface‐bound defects and acid‐base properties. The removal efficiency of Hg0 vapor depends among others, on the flue gas composition and temperature. CeO2 can be incorporated into known materials in such a way that the abatement process can be effective at different operating conditions. Hence, the scope of this account is to discuss the role of CeO2 as a promoter, active phase and support in the design of composite Hg0 sorbents/catalysts. The elucidation of each of these roles would allow the integration of CeO2 advantageous characteristics to such degree, that tailor‐made environmental solution to complex issues can be provided within a broader application scope. Besides, it would offer invaluable input to theoretical calculations that could enable the materials screening and engineering at a low cost and with high accuracy. Ceria, due its unique properties, has been widely utilized in environmental catalysis. This account focuses on its role as a promoter, active phase and support in the design of composite materials for mercury abatement. The fundamental reaction mechanisms are addressed with the aim of fully exploiting the synergistic effects in versatile environments.