Deactivation and regeneration of a commercial SCR catalyst: Comparison with alkali metals and arsenic

- Alkali and arsenic decrease the amount of Brønsted and Lewis acid sites.
- Reducibility is reduced by alkali but improved by arsenic, leading more N2O.
- Dilute H2SO4 and H2O2 are effective to remove poisons.
- Interactions of poisons and active sites further suppress catalyst reactivity.