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

Increasingly stringent regulation towards nitrogen oxides (NOx) emission is foreseen across the world to mitigate their detrimental effects on environment and human health. Selective catalytic reduction (SCR) of NOx with NH3 is regarded as the most efficient technology for NOx 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 NOx 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 hydro-thermal 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 de-mands in industries.

Automated summary

Increasingly stringent regulation towards nitrogen oxides (NOx) emission worldwide calls for efficient technologies such as selective catalytic reduction (SCR) with NH3. Transition metals supported on small-pore zeolites, especially Cu-SSZ-13, have been successfully applied to NOx abatement in road transport and can be extended to stationary sources. However, the stability and activity of such catalysts need to be revisited and tuned to accommodate the complex operating conditions in various industries. This review critically discusses the poisoning and deactivation mechanisms of zeolite-based SCR catalysts, aiming to establish the link between current catalysts and the demands in industries.