The influence of chromium substitution on an iron–titanium catalyst used in the selective catalytic reduction of NO

A series of Cr-substituted Fe–Ti compounds were prepared by the co-precipitation method and were systematically investigated as catalysts for the selective catalytic reduction (SCR) of NO by NH3. A variety of analytical techniques revealed that the Cr substitution amount affects the N2 selectivity, SCR activity, redox behavior of NH3/NOx, adsorption ability, and structure of catalysts in terms of surface properties, porosity, mobility of lattice oxygen, oxidative ability of Cr species, ratio of Brønsted acid sites and Lewis acid sites, NOx adsorption capacity, and structural disorder and distortion. In a series of FeaCr1−aTiOx (a = 1, 0.75, 0.5, 0.2, 0) catalysts, Fe0.5Cr0.5TiOx showed the highest activity because of the optimized interactions of Fe, Cr, and Ti species in this catalyst.