We have studied oxygen interaction with Au crystals (field emitter tips) using time-resolved (atom-probe) field desorption mass spectrometry. The results demonstrate no adsorption to take place on clean Au facets under chosen conditions of pressures (p < 10(-4) mbar) and temperatures (T=300-350 K). Steady electric fields of 6 V/nm do not allow dissociating the oxygen molecule. The measured O-2(+) intensities rather reflect ionization of O-2 molecules at critical distances above the Au tip surface. Certain amounts of Au-O-2 complex ions can be found at the onset of Au field evaporation. Calculations by density functional theory (DFT) show weak oxygen end-on interaction with Au-10 clusters (Delta E=0.023 eV) and comparatively stronger interaction with Au-1/Au(100) model surfaces (Delta E=0.25 eV). No binding is found on \210\ facets. Including (positive) electric fields in the DFT calculations leads to an increase of the activation energy for oxygen dissociation thus providing an explanation for the absence of atomic oxygen ions from the field desorption mass spectra. (c) 2006 American Institute of Physics.