Spectroscopic study on thermal reaction and desorption of sulfur/Rh(1 0 0) induced by oxygen-containing molecules

The surface reaction and desorption of sulfur on Rh(1 0 0) induced by O2 and H2O are investigated with X-ray photoelectron spectroscopy (XPS) technique. The Rh(1 0 0) sample covered with atomic sulfur is prepared by means of the exposure to H2S gas, and subsequently the sample is annealed under O2 or H2O atmosphere. The XPS results show that atomic sulfur adsorbed on Rh(1 0 0) reacts with O2 and desorbs from the surface at 473 K or more. On the other hand, atomic sulfur can not be removed from Rh(1 0 0) surface by H2O at any temperature.