This work presents the promoting effects of the addition of a second metal to the catalyst and of the addition of SO2 to the feed during the SCR of NO with ammonia at low temperature over vanadium supported on carbon-coated monoliths. Comparing both effects, the addition of SO, in the feed is a much more effective promoter that the addition of a second metal to vanadium. Upon introduction of 400 ppm SO2 there is around a three-fold increase in the specific activity of the catalyst. It was found that mesoporosity of carbon support plays a key role on the durability of the promoting effect of SO2 at low temperatures. (c) 2005 Elsevier B.V. All rights reserved.