XPS Study of CO Adsorption on Simple Metals

Abstract

The interaction of carbon monoxide with clean simple metal surfaces, in the present case aluminium and magnesium, is studied with X-ray photoelectron spectroscopy through the analysis of the binding energies and relative intensities of the core level lines from the adsorbate and the substrate. It appears that the interaction of CO is different at room temperature with aluminium and magnesium by the number of adsorption states recorded on the two different metals (2 for Mg, and 1 for Al). We note an adsorption process differing with the preparation procedure (evaporation or sputter-cleaning) of the surface before the adsorption. A comparison is made with selected results reported for transition metals, and the importance of metal electronic backdo-nation (i.e. the existence, or not of d electrons in the metal) is discussed. © 1978 The Japan Society of Applied Physics.