Studies of molecular oxygen adsorbed on Cu surfaces

Molecular oxygen adsorbed on (110) and polycrystalline Cu surfaces has been investigated by UPS, XPS, AES, HREELS and LEED. Molecularly adsorbed O2 on the (110) surface shows the characteristic three-peak HeII spectrum due to πg, πu and σg orbitals, accompanied by an O-O stretching frequency at 660 cm-1. On the polycrystalline Cu surface, adsorbed O2 shows the three peak HeII spectra with a considerably smaller separation between the πu and σg band and two O-O stretching bands at 610 and 880 cm-1. O2 adsorbed on the Cu(110) surface gives rise to a (1×1) LEED pattern and characteristic Kπ∗π∗ transition in the Auger spectrum.