This Master’s thesis investigates the deactivation of Fe-based SCR catalysts exposed to impurities originating from bio-based fuels. The study focuses on Fe-SCR catalysts
supported on Beta zeolite and examines the combined effects of sulphur, alkali metals (Na, K, Ca) and phosphorus on catalytic performance and structural stability. Catalyst activity was evaluated through NOX, NH3 and N2O conversion measurements, while structural and surface changes were analysed using DRIFTS, BET, XRD and SEM– EDS. Deactivation was found to result from catalyst site poisoning and a loss of microporous surface area. The catalyst activity ranking of poisoned samples was K > Ca > S > P > Na. Sodium and phosphorus caused the strongest deactivation by suppressing catalyst activity and reducing zeolitic microporosity, whereas potassium and calcium do not have so significant impact.