He Hong, academician research team of the center for ecological environment research, Chinese Academy of Sciences, has made important progress in the field of selective catalytic reduction of nitrogen oxides

Nitrogen oxide (NOx) is a kind of important air pollutants, which takes part in the formation of a series of air pollution, such as acid rain, photochemical smog, haze and so on, which seriously endangers the ecological environment and human health NO x produced by human activities mainly comes from the combustion emissions of stationary sources such as power plants and mobile sources such as motor vehicles Ammonia selective catalytic reduction of nitrogen oxides (nh3-scr) is the main technology to remove fixed source and mobile source NOx The most widely used catalyst system is vanadium based catalyst However, due to the complexity of SCR reaction, the understanding of the micro reaction mechanism of vanadium based NH3 SCR is still unclear On the other hand, due to the high loading of vanadium based catalysts will catalyze the conversion of SO 2 to so 3, and the biological toxicity of vanadium oxides, it is an urgent need to develop new vanadium based catalysts with low vanadium loading and excellent low temperature activity The research team of academician he Hong of the ecological environment research center of the Chinese Academy of Sciences has made important progress in the research of NH 3-scr The research results were recently published in the comprehensive academic journal Science Advanced (DOI: 10.1126 / sciadv.aau4637) By means of quantum chemical calculation method, the whole process of micro elementary reaction of NO x removal with V-based SCR catalyst is clarified at the atomic level It is clear that the coupling of vanadium species in the polymerization state shortens the reaction path of active site regeneration and significantly reduces the critical energy barrier Theoretical and experimental results show that the catalytic activity of oligo vanadium species is significantly higher than that of monomer vanadium species, which is the active site of NO x removal by SCR at low temperature Under the guidance of theory, the research team has successfully synthesized the active center structure of low-temperature vanadium oxide by controlling the sulfur content on the catalyst surface, and achieved a significant increase in low-temperature SCR activity at low vanadium loading (1 wt%) (Figure 2) The research results have been successfully applied to the development and mass production of SCR catalyst with low vanadium and high activity for tail gas purification of heavy diesel vehicles The research was supported by NSFC and national key R & D program.