Deactivation of Cu SCR catalysts based on small-pore SSZ-13 zeolites: A review

Increasingly stringent regulation towards nitrogen oxides (NO_x) emission is foreseen across the world to mitigate their detrimental effects on environment and human health. Selective catalytic reduction (SCR) of NO_x with NH₃ is regarded as the most efficient technology for NO_x abatement in both mobile and stationary sources. As the state-of-art SCR catalyst, transition metals supported on small-pore zeolites, especially Cu on chabazite SSZ-13 (Cu-SSZ-13), have been successfully applied to NO_x abatement in road transport. Their application can be expanded to stationary sources due to the gradual phase-out of petrol/diesel vehicles worldwide between 2030 and 2035. Accordingly, the stability and activity of such catalysts need to be revisited and tuned to accommodate the complex operating conditions in various industries such as wider temperature windows and the more complex compositions of the exhausts. This review focuses on the poisoning and deactivation of zeolite-based SCR catalysts, especially Cu-SSZ-13. State-of-the-art of different mechanisms of deactivation (including hydrothermal ageing, sulphur poisoning, hydrocarbon poisoning and chemical poisoning) are discussed critically, attempting to establish the link between current zeolite-based SCR catalysts and the possible application demands in industries.