Supported catalysts for simultaneous removal of SO2, NOx, and Hg0 from industrial exhaust gases: A review

The simultaneous removal of SO2, NOx and Hg0 from industrial exhaust flue gas has drawn worldwide attention in recent years. A particularly attractive technique is selective catalytic reduction, which effectively removes SO2, NOx and Hg0 at low temperatures. This paper first reviews the simultaneous removal of SO2, NOx and Hg0 by unsupported and supported catalysts. It then describes and compares the research progress of various carriers, eg., carbon-based materials, metal oxides, silica, molecular sieves, metal-organic frameworks, and pillared interlayered clays, in the simultaneous removal of SO2, NOx and Hg0. The effects of flue-gas components (such as O2, NH3, HCl, H2O, SO2, NO, and Hg0) on the removal of SO2, NOx, and Hg0 are discussed comprehensively and systematically. After summarizing the pollutant-removal mechanism, the review discusses future developments in the simultaneous removal of SO2, NOx and Hg0 by catalysts.