A review on application of cerium-based oxides in gaseous pollutant purification

The air quality is getting increasingly worse due to large consumption of fossil fuels for residential and industrial application. The resultant gaseous pollutants, e.g., nitrogen oxides, heavy metals, sulfides, carbon dioxide, carbon monoxide, volatile organic compounds, pose serious threats to human health. Thus, the development of corresponding cost-effective air purification technology is imminent. Cerium oxide is considered as one of the most promising heterogeneous catalysts owing to its environmental friendliness, surface-bound defects, excellent redox ability, remarkable oxygen storage capacity, and so forth. Cerium-based oxides, such as cerium oxide supported oxides (X/Ce), supported cerium oxides (Ce/X) and composite cerium oxides (Ce-X), have been widely used as catalysts for the elimination of gaseous pollutants. In this review, the applications of various cerium-based oxides in gaseous pollutant control are systematically reviewed, including selective catalytic reduction (SCR) of NOx with NH3, adsorption and catalytic oxidation of Hg0, CO oxidation, CO2 conversion, selective oxidation of H2S, and catalytic combustion of volatile organic compounds (VOCs). This review is intend to provide some value references for the design and synthesis of novel cerium-based catalysts for gaseous pollutant purification in future.