Tailored Alkali Resistance of DeNO Catalysts by Improving Redox Properties and Activating Adsorbed Reactive Species.

It is still challenging to develop strongly alkali-resistant catalysts for selective catalytic reduction of NO with NH. It is generally believed that the maintenance of acidity is the most important factor because of neutral effects of alkali. This work discovers that the redox properties rather than acidity play decisive roles in improving alkali resistance of some specific catalyst systems. K-poisoned Fe-decorated SO-modified CeZr oxide (Fe/SO/CeZr) catalysts show decreased acidity but reserve the high redox properties. The higher reactivity of NH species induced by K poisoning compensates for the decreased amount of adsorbed NH, leading to a desired reaction efficiency between adsorbed NH and nitrate species. This study provides a unique perspective in designing an alkali-resistant deNO catalyst via improving redox properties and activating the reactivities of NH species rather than routinely increasing acidic sites for NH adsorption, which is of significance for academic interests and practical applications.