A critical review on the heterogeneous catalytic oxidation of elemental mercury in flue gases.

Nowadays, an increasing attention has been paid to the technologies for removing mercury from flue gases. Up to date, no optimal technology that can be broadly applied exists, but the heterogeneous catalytic oxidation of mercury is considered as a promising approach. Based on a brief introduction of the pros and cons of traditional existing technologies, a critical review on the recent advances in heterogeneous catalytic oxidation of elemental mercury is provided. In this contribution, four types of Hg oxidation catalysts including noble metals, selective catalytic reduction (SCR) catalysts, transition metals, and fly ash have been summarized. Both the advantages and disadvantages of these catalysts are described in detail. The influence of various acidic gases including SO2, SO3, NH3, NOx, HCl, Cl2, etc. have been discussed as well. We expect this work will shed light on the development of heterogeneous catalytic oxidation of elemental mercury technology in flue gases, particularly the synthesis of novel and highly efficient Hg(0) oxidation catalysts.