Unraveling alkali-tolerance role of zeolite coupling CeWOx catalyst for NOx reduction

Abstract

The deactivation of the selective catalytic reduction (SCR) catalysts in the presence of alkali metal is still unsolved to date, there is no fully effective strategy to remedy it. Herein, a series of novel zeolite coupling CeWOx catalysts (CeWOx@ZSM-5) with core-shell structures was synthesized by a simple method. The proposed CeWOx@ZSM-5 catalyst exhibited superior deNOx performance and K-poisoning resistance, which are attributed to the synergy between the shell and active components. The zeolite shell with abundant acid sites can act as a sacrificial agent to preferentially bind to K, thereby decelerating/inhibiting the alkali metal poisoning process of the catalyst. Even after loading 1 wt% K, the NOx conversion remained as high as > 80% at 300–500 °C over the CeWOx@ZSM-5 catalyst under humid conditions. The novel zeolite coupling CeWOx catalyst may serve as a workable reference for new, efficient, and highly poisoning-resistant SCR catalysts for practical application.