Influence of the deposition of Na+ ions on gamma-Al2O3 on its surface properties and catalytic activity in oxidation of CH2Cl2 by gas phase oxygen has been studied. IR spectra indicate that the concentration of OH groups is significantly reduced and Lewis acidity, related to exposed Al ions, is simultaneously decreased. Therefore, total catalytic activity is strongly depressed, no CH3Cl is formed as intermediate product, Cl-2 appears in the products which is absent on pure gamma-Al2O3 and the amount of CO2 is at all temperatures higher than that of CO. This indicates that parallel to the two mechanisms, operating in case of gamma-Al2O3 and starting with mono- and bidentate adsorption of CH2Cl2 through its chlorine atoms on Lewis sites, a third reaction pathway appears starting with adsorption through hydrogen atoms.