Sulfur poisoning of carbon monoxide adsorption on Ni(111)

• Published in: Journal of catalysis Vol. 53; no. 3; pp. 287 - 294
• Main Authors: Erley, W., Wagner, H.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.01.1978
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/0021-9517(78)90101-X

CO adsorption on Ni (111) precovered with varying amounts of sulfur has been investigated using LEED, AES, flash desorption, and work function measurements. Sulfur strongly reduces CO adsorption and blocks it completely for θ s > 0.3. Besides a single CO adsorption state observed for the clean surface flash desorption spectra reveal a second state at lower energy for θ s > 0.1. With increasing sulfur coverage the following sequence of LEED structures is observed: p(2 × 2), (3 1 2 × 3 1 2 ) R 30 °, c(20 × 2) . The latter complex pattern, already described in previous publications and attributed to a reconstructed surface, could also be obtained by additional CO adsorption onto the p(2 × 2) sulfur structure. In connection with further experimental findings it is proposed that the complex pattern results from a coincidence structure of a chemisorbed sulfur over-layer.