Photoelectron spectromicroscopy of electrochemically induced oxygen spillover at the Pt/YSZ interface

Scanning photoelectron microscopy (SPEM) has been applied to study the proc esses at the interface between the oxygen ion conducting solid electrolyte YSZ (yttrium stabilized zirconia) and a microstructured 500 Angstrom thick Pt film on top of the YSZ when electrical potentials are applied. An electr ochemically induced oxygen spillover onto the Pt surface has been observed upon electrochemical pumping with a positive potential applied to the Pt fi lm. The spillover species was characterized in X-ray photoelectron spectros copy by an Ols binding energy of 530.4 eV which is identical to that of che misorbed oxygen from the gas phase. (C) 2000 Elsevier Science B.V. All righ ts reserved.