THERMALLY DEPENDENT ADSORPTION OF (CH3)2S ON OXYGEN PRE-COVERED Rh SURFACE STUDIED BY XPS AND NEXAFS

Abstract

The adsorption reaction of (CH3)2S on oxygen pre-covered Rh(111) surface has been investigated by XPS and S K-edge NEXAFS techniques. The dissociation of (CH3)2S to methanethiolate and atomic sulfur occurs without regard to the coverage of pre-covered oxygen at 90 K. XPS and NEXAFS results indicate that some of the adsorbates bond to atomic oxygen via their sulfur atom. It seems that adsorbates bonding to atomic oxygen are difficult to desorb from the surface, even if it is heated up to 200 K.