Structure and Chemical State of the Pt(557) Surface during Hydrogen Oxidation Reaction Studied by in Situ Scanning Tunneling Microscopy and X-ray Photoelectron Spectroscopy

The surface structure of Pt(557) during the catalytic oxidation of hydrogen was studied with in situ scanning tunneling microscopy and X-ray photoelectron spectroscopy. At 298 K, the surface Pt oxide formed after exposing Pt(557) to approximately 1 Torr of O-2 can be readily removed by H-2, at H-2 partial pressures below SO mTorr. Water is detected as the product in the gas phase, which also coadsorbs with hydroxyl groups on the Pt(557) surface.