ELS study on chemisorbed state of CO on Cr(110)

The chemisorbed state of CO on a Cr(110) surface has been investigated at 300 K by electron energy loss spectroscopy (ELS) with the in-situ combined supplementary techniques. The ELS spectrum of the Cr(110) surface after CO adsorption is characterized by the peaks at 2, 4.4, 6–7, 9, 11, 14.5, 19 and 23 eV, and is found to be practically the same as that of the oxygen covered surface. The C-KLL Auger spectra obtained in the range 0.1–900 L CO agree with those of metal carbides. These results are considered to indicate that CO is dissociatively chemisorbed on the Cr(110) surface throughout the whole exposure region examined. The average sticking probability of CO on Cr(110) is 0.7 at below 0.5 L, and the maximum work function increase at 1 L is ~0.1 eV. The adsorbed state of O atoms produced from dissociative adsorption of CO is also discussed.