The electronic structure and reactivity of the oxygen-modified Mo2C(0Â 0Â 0Â 1) surface

Oxygen adsorption on Mo2C(0 0 0 1) has been investigated with angle-resolved photoemission spectroscopy (ARPES). When the surface is reacted with O2, the O 2p-induced states are formed at 4.1 and 5.3 eV at the Γ¯ point. The emissions around the Fermi level are also intensified by oxygen adsorption, which is due to the formation of a partially filled state. It is found that the reactivity of the surface toward H2O adsorption is much enhanced by pre-adsorption of oxygen. The reactivity is found to be maximized at θO ∼ 0.2.