Review of the Irbased catalyst in selective catalytic reduction of NO with CO

The CO selective catalytic reduction of NOx (CO-SCR) technique has attracted considerable attentions in reduction denitration for flue gas from stationary source such as steel sintering/pellet emissions and coking flue gas, and the most outstanding characteristics of these emissions are low temperature, high oxygen content and high CO concentration. Ir-based catalysts, one class of precious metal catalysts, have become one of the hotspots in catalytic reduction denitration due to their excellent antioxidant capacity and high catalytic activity in the CO-SCR reaction system. This review was devoted to the catalytic performance of three types of Ir-based catalysts in CO-SCR removal of NOx, including single carrier, composite carrier and composite active component. The effects of the preparation conditions and reaction conditions on the CO-SCR denitration performance of the Ir-based catalysts were also summarized. Finally, the reaction mechanism of NOx on the surface of the Ir-based catalysts was briefly described. The paper points out that the catalyst can be modified by various methods, and the cost can be reduced by reducing the Ir loading and the reaction temperature window or improving the catalytic activity, which provides reference for the industrial application of the Ir-based catalyst CO-SCR. © 2019, Chemical Industry Press. All right reserved.