The effects of the source of Te and the dispersion of TeO2 on fabricating Mo-V-Te and Mo-V-Te-Nb mixed metal oxide (MMO) catalysts for propane partial oxidation to acrylic acid (AA) were systematically studied. In order to modify the dispersion of TeO2 in the preparation medium, wet-milling and ultrasonic-assisted dispersion of TeO2 were adopted. The selected samples were characterized by means of BET, XRD, ICP/XRF, XPS, SEM, H-2- and C3H8-TPR and calorimetric NH3 adsorption. It was clearly demonstrated that different sources of Te and dispersion of TeO2 in preparation showed significant impact on the physicochemical properties (phase composition, bulk/surface elemental concentration, reactivity of lattice oxygen, and surface acidity) and catalytic activity of the MMO catalysts. The employment of ultrasonic treatment was proved to be effective for making more active and selective Mo-V-Te/Mo-V-Tc-Nb catalysts for the target action. (c) 2006 Elsevier B.V. All rights reserved.