Alkali-resistant NOx reduction over FeVO4/TiO2 catalysts via regulating the electron transfer between Fe and V

The presence of alkali metals in exhaust gas from stationary resources causes a grand challenge for the practical application of selective catalytic reduction (SCR) of NOx with NH3. Here, alkali-resistant NOx reduction has been successfully implemented via tailoring the electron transfer over Fe and V species on FeVO4/TiO2 catalysts. The strong interaction between Fe and V induced electron transfer from V to Fe and strengthened the adsorption and activation of NH3 and NO over active VOx sites. In the presence of K2O, the strong electron withdrawing effect of Fe offset the electron donating effect of K on the VOx species, thus protecting the active species VOx to maintain the NOx reduction ability. The enhanced adsorption and activation of NH3 allowed SCR reaction to proceed via E-R mechanism even after K2O poisoning. This work elucidated the electronic effects on the alkali metals resistance of traditional ferric vanadate SCR catalysts and provided a promising strategy to design SCR catalysts with superior alkali resistance.