Synthesis Of Low-medium Temperature Copper Based SCR Catalysts And Its Denitration Performance

Rapid modernization and urbanization is expecting,the increase in energy consumption quantity year in year out.While utilizing the heat energy and electricity generated during the incineration process,secondary pollution of nitrogen oxides(NOx)occurs during the waste incineration,affecting human health and the environmental ecosystem.The industrial flue gas denitration technology-selective catalytic reduction(SCR)device is mostly installed after the dust removal and desulfurization device,when the flue gas reaches the denitration device,the temperature is low.Obviously,the existing high-temperature catalyst can not meet the actual demand,and develop an SCR denitration catalyst suitable for application at low-medium temperatures,which can effectively solve the technical problems faced by the current denitration process.Therefore,in this study,we used LDHs as precursor to develop a novel copper-based SCR catalyst with highly effective dispersed active components by calcination.According to the characteristics of municipal waste incineration flue gas components,the different functional active metal ions are introduced into the LDHs materials by means of the regulatable characteristics of metal cations in the LDHs materials,thereby improving the low-medium temperature activity the resistanceperformance of the catalyst.The LDHs-derived CuAlOx catalyst was synthesized by coprecipitation method,regulation of metalelement ratio and calcination temperature.The preferred Cu4Al1Ox catalyst exhibited good catalyticactivity and excellent thermal stability.When the calcination temperature is 400?,the maximum NOx conversion rate of Cu4Al1Ox catalyst is 91.1%;when the calcination temperature is 700?,the NOxconversion rate is still as high as 84.7%.In addition,the low temperature catalytic performance and resistance performance of the CuAlOx catalyst still dire need to be further revamped.In this work,the low temperature performance and resistance performance of copper-based catalystswere studied.The results revealed that the manganese modified CuMnAlOx catalyst has excellent low temperature NH3-SCR performance.Meanwhile,the preferred Cu2Mn0.5Al0.5Ox catalyst has a NOx conversion of up to 91.2%at a test temperature of 150?;the titanium modified CuMnTiOx catalyst exhibits good catalytic activity and excellent sulfur stability.The preferred Cu1Mn0.5Ti0.5Ox catalyst has a NOx conversion of 90%at a test temperature of 200 0C.After 12 h of operation in the presence of 100 ppm SO2,the NOx conversion decreased slightly and stabilized at 70%;the magnesium modified CuMgMnAlOx catalyst has excellent low temperature performance and sulfur resistance.The preferred Cu0.5Mg1.5Mn0.5Al0.5Ox catalyst has a NOx conversion of 96.6%at a test temperature of 150?.The NOx conversion was 64.2%in the presence of 100 ppm SO2+5%H2O for 18 h;the cerium-modified Ce/Cu4Al1Ox catalyst had excellent catalytic activity and resistance to HCl and SO2.The preferred Ce2/Cu4Al1Ox catalyst has a NOx conversion of 95.3%at 200?,and Ce2/Cu4Al1Ox still has a NOx conversion of 57.2%in the presence of 100 ppm HC1+100 ppm SO2+5%H2O after 9 h.Moreover,in this research,the reaction mechanism and resistance mechanism of various transition metal modified catalysts were also investigated.The results illustrated that the presence of highly dispersed active species,strong redox ability,oxygen vacancies and acidic sites may be the factors for the excellent denitration performance after catalyst advance modification.