Physicochemical Features and NH3-SCR Catalytic Performance of Natural Zeolite Modified with Iron—The Effect of Fe Loading

In modern dual-pressure nitric acid plants, the tail gas temperature usually exceeds 300 °C. The NH3-SCR catalyst used in this range must be resistant to thermal deactivation, so commercial vanadium-based systems, such as V2O5-WO3 (MoO3)-TiO2, are most commonly used. However, selectivity of material significantly decreases above 350 °C due increase rate side reactions, oxidation ammonia NO and formation N2O. Moreover, vanadium compounds toxic for environment. Thus, management is complicated. One alternatives V2O5-TiO2 catalysts natural zeolites. These materials abundant environment thus relatively cheap easily accessible. Therefore, aim study was design a novel iron-modified zeolite reduction NOx emission from plants via NH3-SCR. determine influence iron loading zeolite-supported on its catalytic performance conversion. investigated support firstly formed into pellets then impregnated with various contents Fe precursor. Physicochemical characteristics were determined by XRF, XRD, low-temperature N2 sorption, FT-IR, UV–Vis. tested laboratory scale within 250–450 using gases pilot plant. results indicated that presence species, including isolated Fe3+ introduced FexOy oligomers, contributed efficient reduction, especially high-temperature range, where conversion exceeded 90%.