Research Progress of Ceria-Based Catalysts in the Selective Catalytic Reduction of NOx by NH3

Nitrogen oxides (NOx), which are emitted from stationary sources (such as coal-fired power plant flue gases) and mobile sources (such as motor vehicle exhausts), cause serious atmospheric pollution. As a result, it is very important to control the emissions of NOx. Some studies have suggested that NH3-selective catalytic reduction (NH3-SCR) of NOx is one of the best techniques for this purpose. Ceria-based catalysts are widely used in the NH3-SCR reaction because of their good redox ability, suitable surface acidity, high oxygen storage or release capacity, and rich resource reserves. Investigating the role of ceria component in this reaction is important to understand the nature of the related catalytic process, and provides a valuable scientific reference for the optimization of existing catalysts and the design of novel catalysts. Based on the different roles of ceria in NH3-SCR catalysts, we have performed a systematic review of the latest research progress of ceria-based catalysts in the NH3-SCR reaction for the following aspects: CeO2 used as supports, ceria-based mixed oxides, surface loading components (additives and active species), and ceria-based catalysts with special structures. Finally, we discuss the future directions of this field.