# An XPS Study of the Adsorption of Oxygen on Silver and Platinum Surfaces Covered with Potassium or Cesium

Ayyoob, M and Hegde, MS (1983) An XPS Study of the Adsorption of Oxygen on Silver and Platinum Surfaces Covered with Potassium or Cesium. In: Surface Science, 133 (2-3). pp. 516-532.

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## Abstract

Adsorption of oxygen has been investigated on silver and platinum surfaces covered with potassium or cesium by X-ray photoelectron spectroscopy. Three types of oxygen species, viz., molecularly chemisorbed, $O^{\delta-}_2$, dissociatively chemisorbed, $O^{x-}$ $(\delta, x < 2)$, and oxide (or sub-surface oxygen), $O^{2-}$, are seen on potassium covered silver surface. While at smaller cesium coverages, both dissociatively chemisorbed, $O^{x-}$, and the oxide oxygen, $O^{2-}$, have been observed on silver, the dissociatively chemisorbed, $O^{x-}$, and the molecularly chemisorbed oxygen, $O^{\delta-}_2$, are seen at very high cesium coverages. The dissociated oxygen is the main species present on platinum covered with either potassium or cesium. Surface concentrations of oxygen on both metal surfaces have been estimated over a wide range of alkali coverages $(1 \times 10^{14}$ to $1.8 \times 10^{15}$ $atoms/cm^{2})$ and temperatures (300 to 800 K).

Item Type: Journal Article Copyright of this article belongs to Elsevier. Division of Chemical Sciences > Solid State & Structural Chemistry Unit 07 Jul 2008 19 Sep 2010 04:46 http://eprints.iisc.ernet.in/id/eprint/14801