Experimental Study On Mn/Cu-ZSM5 Catalyst For Rapid Denitrification

As the main pollutant in the atmosphere, NOx is the main factor causing the formation of acid rain, producing chemical smog, and causing a series of environmental pollution problems. Our country has modified the requirement of the pollutant discharge standard, the standard requirement is gradually strict, and the relevant laws and regulations are promulgated to focus on the control of pollutants in NOx emissions. There are mainly commercial vanadium based catalysts, but the low temperature conditions are low efficiency, the SO2, dust and other effects, so it is necessary to seek more efficient, anti H2O, anti SO2 and other advantages of the new catalyst.In this paper, a fast SCR reaction method is explored, and the experimental platform is set up according to the demand of the reaction equation. At the same time, with the advantages of high water resistance, large specific surface area, high void volume, the molecular sieve is used as the carrier of catalyst, and the Cu element with high reducibility is used as the active ingredient, and then, it will be doped with a variety of different metal elements. The Cu-ZSM5 catalyst and the modified catalyst M/Cu-ZSM5 were used to study the performance for denitrification in order to explore the catalytic properties and physical structure of the catalyst.The results show that the Cu element is dispersed in molecular sieve in the form of oxide, when the loading amount of Cu is more than 8wt% in the samples, it was aggregated by large particle as CuO crystals, and the loading is less than 8wt% in the samples, CuO is not detected as the crystal phase. The presence of NO2 can improve the denitrification efficiency. By using fast SCR process, the catalyst can reduce the temperature of denitrification, and the catalyst with 8wt% Cu loading showed the best catalytic performance for fast SCR reaction, at 200℃, the denitrification efficiency reached on 93%. The effect of Cu element on the Lewis acid sites, which can adsorb NO, is conducive to the improvement of the efficiency of denitrification. Doping of different metal elements on the Cu based catalysts was studied. The results showed that the Mn elements can improve the performance of the catalyst.Based on Cu-ZSM5 catalyst, the effect of doping Mn element of the catalyst was studied on the structure and properties. The results show that the doping of Mn element can effectively improve the performance of Cu-ZSM5 catalyst, which can promote the dispersion of CuO crystal phase, and produce the Cu-Mn composite oxide, which is the main component of the catalytic reaction, and the catalytic performance of the catalyst is changed. At the same time, the influence of the calcination temperature on the catalyst was studied. It is found that the lower calcination temperature is beneficial to the dispersion of CuO crystal phase, which is due to the different oxide produced by Mn element at different calcination temperatures, and the influence for CuO is different.