Simultaneous removal of SO2 and NO from flue gas using CeO2 promoted CuO/γ-Al2O3 catalysts

The simultaneous desulfurization and denitration performance of the Cu8Ce3 and Cu8Ce3S catalysts were studied in a fixed-bed reactor. The test results show that the presence of SO2 has a poisoning effect on the denitration performance of Cu8Ce3 when the flue gas temperature is below 350°C, but this kind of toxic effect is reversible. The root cause is that the sulfate species such as CuSO4 and Ce2(SO4)2 formed on the surface of Cu8Ce3S have a lower denitration activity below 350°C than CuO and CeO2. However, Changes in catalyst pore structure after desulfurization could not affect the amount of NH3 adsorbed significantly. The formation of SO4 2- on the Cu8Ce3S catalyst surface increased the number of Lewis acid sites on the catalyst surface, which improved the catalyst's strength ability to react with NH3 to ensure that Cu8Ce3S has a faster reaction rate than that of Cu8Ce3 above 350°C. The catalytic selectivity of Cu8Ce3S for NH3 is better than that of Cu8Ce3 at 350-500°C, which is the fundamental reason for the improvement of denitration efficiency at high temperatures.