Synthesis, electronic and chemical properties of MoOx clusters on Au(111)

A novel procedure for the synthesis of molybdenum oxide nanoparticles has been developed. Mo nanoparticles were prepared on Au(1 1 1) by dissociation Of MO(CO)(6) molecules at 500 K. These Mo nanoparticles were found inactive towards oxygen according to results of synchrotron-based high-resolution photoelectron spectroscopy (PES). There was no sign of molybdenum oxide formation after an exposure to 150 L of oxygen at 300-850 K. However, these Mo nanoparticles can be oxidized by reaction with NO2 at 500 K to form molybdenum oxides, MoO2 or MoO3. The stability of the MoO3 particles upon annealing was further investigated by PES. The fully oxidized MoO3 clusters do not react with ethylene. (C) 2002 Elsevier Science B.V. All rights reserved.