Adsorption and Interaction of Hydrogen and Oxygen on the Surface of Separate Crystalline Gold Nanoparticles

摘要

Crystalline 4- to 5-nm gold nanoparticles supported on graphite and oxidized silicon have been obtained by the impregnation method. Specific features of the adsorption and interaction of H-2 and O-2 on the Au surface have been investigated by scanning tunneling microscopy, Auger electron spectroscopy, and mass spectrometry. Hydrogen adsorbs dissociatively on separate Au nanoparticles. The Au-H bond energy is similar to 1.7 eV. Oxygen adsorbs on the separate Au nanoparticles after hydrogen adsorption. The support nature has a significant effect on the reactivity of the H-2 and O-2 molecules adsorbed on the surface of the Au nanoparticles. A sufficient condition for water formation from oxygen and hydrogen on Au/SiO2/Si is that Au/SiO2/Si is exposed to H-2 and then to O-2. As distinct from what is observed for Au/SiO2/Si, water on the Au/graphite surface forms solely due to the successive adsorption of H-2, O-2, and H-2.