Thermodesorption spectroscopy (TDS) and temperature-programmed reaction (TPR) using a beam forming gas doser and oxygen isotopes O-18(2) and O-16(2) have been applied for studying the titration of adsorbed O-ads and subsurface oxygen subs on a reconstructed Pd(110) surface. Subsurface oxygen appears to be non-reactive. However, as the reaction proceeds, it comes onto the surface and interacts with adsorbed CO. Numerical simulations have been applied to investigate the O-subs -> O-ads transfer kinetics. On the reconstructed surface the stage O-subs -> O-ads is reversible, and its rate is linearly dependent on the concentration of surface sites freed during the reaction O-ads + COads -> CO2. The temperature dependencies of direct and reversed reaction rate constants have been determined. As the adsorbed oxygen concentration decreases to some threshold value, a self-accelerated irreversible subsurface oxygen outcome occurs caused by a surface reconstruction to the structure (1 x 1). The kinetic equation for the process has been suggested. The temperature dependence of the critical surface oxygen coverage initiating the surface reverse reconstruction has been determined. (C) 2016 Elsevier B.V. All rights reserved.