ADSORPTION OF ACETIC-ACID ON HYDROXYLATED NIO(111) THIN-FILMS

Ni(100) has been exposed to O-2 to form similar to 3 monolayer crystal line NiO(111) thin films and the films have been characterized by HREE LS, XPS, AES and acetic acid adsorption. The NiO(111) is Ni2+-polar an d contains approximately 65% of the surface nickel sites terminated by isolated OH with substantial ionic character. The hydroxyls appear to serve a stabilizing role for the thermodynamically metastable NiO(111 ) surface and also to provide a condensation mechanism for interaction with the acetic acid. While there are Ni2+-OHads surface sites availa ble for adsorption, at least some of the hydroxyls associated with the NiO(111) film are occluded or otherwise inaccessible. The XP and HREE L spectral data support an assignment of adsorbate formation to a brid ging acetate species.