A study of the mechanism of iron‐based sulfate catalyst for selective catalytic reduction of NO with NH₃

Abstract

The catalytic activity of iron-based sulfate catalyst in selective catalytic reduction (SCR) of NO with NH 3 in the presence/absence of O 2 was investigated. Powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFT) are applied to study the ironbased sulfate catalyst. The iron-based sulfate catalyst shows considerable catalytic activity for the SCR reaction at 350-450 • C in the presence of O 2 . NO and NH 3 reacted with the stoichiometry ratio of 1 : 1 over iron-based sulfate catalysts in the absence of O 2 at 350 • C. By the comparison of NO conversion in the absence/presence of O 2 , an SCR reaction mechanism that included NH 3 oxidation by Fe 3+ and the re-oxidation of Fe 2+ is inferred on the basis of the results obtained from XRD, XPS, and DRIFT. 

Sphere-Shaped Mn3O4 Catalyst with Remarkable Low-Temperature Activity for Methyl–Ethyl–Ketone Combustion

“…For Mn 3 O 4 catalyst (Figure 7a), a strong peak of 3258 cm −1 was due to OH stretching of the Brønsted acid. 59,60 Brønsted acid sites are very important in oxidation catalysis, since the surface acidity, as well as the basic properties, may be responsible for the adsorption/desorption rates of reactants and products, and are a major factor in the activation of hydrocarbons and occurring intermediates. 61 The lowest intensity of OH stretching of the Brønsted acid (3258 cm −1 ) was detected for MEK oxidation on Mn 3 O 4 catalyst at 63,64 and surface carbonate species, 19 respectively.…”