Vanadium oxide supported on mesoporous silica has been synthesized by a novel method and the resulting species tested as catalysts for the partial oxidation of methane to formaldehyde at atmospheric pressure. These catalysts appear to be very active and selective toward formaldehyde. Space-time yields superior to those of all known catalysts of the same type have been obtained. Kinetic parameters all tend to show that the same mechanism postulated for supported vanadium catalyst is taking place. The positive effect of water is also seen. The high performance has been attributed to the wide dispersion of vanadium-isolated species, which are known to be very active and selective, and to greatly superior silanol surface content than in other catalysts. The novel preparation method favors the formation of given isolated species that will be the most active and selective. (c) 2005 Elsevier Inc. All rights reserved.