Revealing the Promotion Effects of Nb on Alkali Resistance of FeVO4/TiO2 Catalysts for NOx Reduction

Abstract

AbstractFeVO4‐based catalysts with a wide temperature window and high SO2 tolerance have attracted increasing attention for the selective catalytic reduction of NOx with NH3. However, the alkali‐resistance of FeVO4‐based catalysts is still challenging. In this study, the K‐resistance of FeVO4/TiO2 was markedly improved via the Nb modification. It was demonstrated that the adsorption and reactivity of NH3/NH4+ and NOx species on K poisoned FeVO4/TiO2 both decreased, which restrained the process of Langmuir‐Hinshelwood reaction path. As a comparison, more adsorption of NH3/NH4+ species and the higher reactivity with gaseous NO maintain the process of Eley‐Rideal reaction path, leading to a satisifactory SCR activity. This work demonstrated an effective route to improve alkali‐resistance via modulating reactivity and reaction path of adsorbed NH3/NH4+ and NOx species over Nb modified vanadate catalysts, which presented a new point for the development of high‐performance alkali‐resistant SCR catalysts.