Study on denitrification performance of rare earth tailings monolithic catalyst prepared with sulfuric acid

Taking rare earth tailings as the raw material, the monolithic catalysts were prepared by extrusion forming method. The effect of concentration of sulfuric acid on the performance of the monolithic catalyst was investigated, and the catalyst was characterized by SEM, XRD, TG-MS, BET, NH3-TPD, NO-TPD, H2-TPR, XPS, ICP, FTIR. The results showed that the denitrification performance of the monolithic catalyst treated with sulfuric acid was greatly improved. The denitrification rate at 400(degrees)C, 86% was got with good mechanical strength. The hematite, magnetite, fluorite react with sulfuric acid to form sulfate, and some Fe-2(SO4)(3) is converted into Fe2O3 after being calcined at 600 C-degrees. Fe-2(SO4)(3) and Fe2O3 are the main active components of the catalyst. CaSO4 and SiO2 make the catalyst have higher mechanical strength. The specific surface area and pore volume of the catalyst increased after being treated with acid. After acidification, the acid sites on the surface increase. There are adsorption species of NO and NH3 on the surface of the catalyst prepared by acid treatment tailings. There are also E-R mechanism and L-H mechanism on the surface of catalyst.