Study on the NO reduction by NH3 on a SO42 −/AC catalyst at low temperature

• The SO42 −/AC catalyst exhibited a higher SCR activity and stability.
• Promoting effect of SO2 depends on the H2SO4 formed on the catalyst surface.
• H2O played a negative role on the SCR activity.

The selective catalytic reduction (SCR) of NO with NH3 at low temperature over a novel SO42 −/AC catalyst (activated coke supported sulfate acid) was investigated especially in the presence of SO2 and H2O. A higher SCR activity and stability were attributed to the cooperation of the oxygen-containing function group and carbon. SO2 promoted SCR activity, which was due to the formation of H2SO4 on the catalyst surface and adsorbed more NH3. The capillary condensation of H2O in the micropores of the catalyst inhibited SCR activity and the reaction of adsorbed NH3 and NO.