This work reports the applicability of reflux to the synthesis of Mo-V-Te-Nb-O metal oxide catalysts for the first time. The well-formed and defined orthorhombic M1 phase, i.e. Te2M20O57 (M = Mo, V, Nb), was found to be better developed when a longer time was used to reflux the mixed metal clusters. The catalysts efficient for propane selective oxidation to acrylic acid, reaching ca. 60% of selectivity to acrylic acid at propane conversion of ca. 50% and at a reaction temperature of 693 K. In addition, a parallel between catalytic activity and catalyst reducibility is also concluded. (C) 2011 Elsevier B.V. All rights reserved.