Efficient NO x Abatement over Alkali-Resistant Catalysts via Constructing Durable Dimeric VO x Species.

The presence of alkali metals in flue gas is still an obstacle to the practical application of catalysts for selective catalytic reduction (SCR) of NO x by NH 3 . Polymeric vanadyl species play an essential role in ensuring the effective NO x abatement for NH 3 -SCR. However, polymeric vanadyl would be conventionally deactivated by the poison of alkali metals such as potassium, and it still remains a great challenge to construct robust and stable vanadyl species. Here, it was demonstrated that a more durable dimeric VO x active site could be constructed with the assistance of triethylamine, thereby achieving alkali-resistant NO x abatement. Due to the rational construction of polymerization structures, the obtained TiO 2 -supported cerium vanadate catalyst featured more stable dimeric VO x species and the active sites could survive even after the poisoning of alkali metal. Moreover, the depolymerization of VO x was suppressed endowing the catalysts with more Brønsted and Lewis acid sites after the poisoning of alkali metal, which ensured the efficient NO x reduction. This work unraveled the effects of alkali metal on the polymerization state of active species and opens up a way to develop low-temperature alkali-resistant catalysts for NO x abatement.