Low-Temperature NH3–SCR of NO on Mesoporous Mn0.6Fe0.4/TiO2 Prepared by a Hydrothermal Method

Mesoporous 30 wt% Mn0.6Fe0.4/TiO2 has been prepared by a novel hydrothermal method using a structure directing agent and characterized by N2 adsorption, SEM, XRD, EDX, H2-TPR and the catalytic activity for the selective catalytic reduction (SCR) of NO by ammonia was measured under power plant flue gas conditions.

Compared to 30 wt% Mn0.6Fe0.4/TiO2 prepared by impregnation, the average pore size was significantly increased. The method of preparation has only a small effect on the catalytic activity at temperatures between 125 and 300 °C. The hydrothermal preparation method leads to a somewhat higher (NH4)2SO4 tolerance at 150 °C compared to the impregnation preparation method.

Regeneration of the (NH4)2SO4 loaded samples by heating to 400 °C was not possible whereas water washing yielded better regeneration. The catalysts are significantly more active than a commercial VWT SCR catalyst at temperatures up to 200 °C, but do not match the activity of the latter at the higher temperatures typically encountered at the high dust position in power plants.