The catalytic activity of material was tested by ESR spectroscopy and investigation of the formation of the super-anion radicals of oxygen on surface zirconia particles in dependence on dopant amount, pressure. UV-visible spectroscopy was used for estimation of optical properties of these materials. It was found the introduction of Y2O3 allows to creation of structure defects in partially stabilized zirconia, and its influence for tetragonal crystals is not monotonic in range 2-4 mol. %. It is connected with boundary of stable tetragonal phase at Y2O3 adding. The pressure is active factor of changing of surface state due to tetragonal – monoclinic transformation and may be used for improvements of catalytic properties of zirconia NPs.