Alkali-Resistant NOx Reduction over SCR Catalysts via Boosting NH3 Adsorption Rates by In Situ Constructing the Sacrificed Sites

Currently, improving the alkali resistance of vanadium-based catalysts still remains as an intractable issue for the selective catalytic reduction of NO x with NH 3 (NH 3 –SCR). It is generally believed that the decrease in adsorbed NH x species deriving from the declined acidic sites is the chief culprit for the deactivation of alkali-poisoned catalysts. Herein, alkali-resistant NO x reduction over SCR catalysts via boosting NH 3 adsorption rates was originally demonstrated by in situ constructing the sacrificed sites. It is interesting that the adsorbed NH x species largely decrease while the NH 3 adsorption rate is well kept over the V 2 O 5 /CeO 2 catalyst by in situ constructing the sacrificed sites. The SCR activity could be maintained after alkali poisoning because in situ constructed SO 4 2– groups would prefer to be combined with K + so that the specific V═O species can endow K-poisoned V 2 O 5 /CeO 2 with high adsorption rate of NH 3 and high reactivity of NH x species. This work provides a new viewpoint that NH 3 adsorption rate plays more decisive roles in the performance of alkali-poisoned catalysts than the amount of NH 3 adsorption and enlightens an alternative strategy to improve the alkali-resistance of catalysts, which is significant to both the academic and industrial fields.