The present study concerns preparation of Pd/V2O5/TiO2 catalysts and activity of the catalysts in selective gas phase oxidation of ethylene by O-2 in presence of water at atmospheric pressure and in the temperature range of 100-200 degrees C. The influence of palladium and vanadia loading and the partial pressures of the reactants on the yield of oxidation products (acetaldehyde and acetic acid) were examined. The surface bound vanadia forms were identified by X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), and FT-Raman spectroscopy. The best activities were achieved with catalysts having near to nominal monolayer vanadia coverage of the support. Time-on-stream catalytic tests and chemical analysis of the fresh and used catalysts proved the structural and catalytic stability of the Pd/V2O5/TiO2 preparations. It was shown that under the conditions of Wacker-oxidation primary product acetaldehyde could be further oxidized to CO2, whereas no consecutive oxidation of product acetic acid proceeded. (C) 2016 Elsevier B.V. All rights reserved.