Zinc is a commonly used metal that is known for its low corrosion rate and one of its most important applications is as a corrosion protecting layer of steel (galvanization).
At atmospheric conditions, zinc is covered by a film that consists of various corrosion products. This protective layer is only stable in a small pH range and gaseous pollutants or particles that acidify the water layer covering the surface can highly influence the degradation of zinc. Among gaseous pollutants, sulfur dioxide has been recognized as the one that has greatest impact on the corrosion of zinc [1].
In this work, room temperature adsorption and coadsorption of water and sulfur dioxide on the single crystal surfaces Zn(0001) and ZnO(0001) are studied with High Resolution X-ray Photoelectron Spectroscopy (HRXPS) in Ultra High Vacuum. The aim of our study is to obtain a better understanding of the interaction of sulfur dioxide and water on the surfaces of zinc and zinc oxide. Zinc oxide is studied because it is a common corrosion product of zinc. It is shown that various SOx species and atomic sulfur are formed on Zn(0001) upon adsorption of SO2 similar to earlier results on polycrystalline zinc [2]. Contrary to that, only SO3 is formed on post-annealed ZnO(0001), as shown earlier [3]. Differences between ion-sputtered and post-annealed surfaces are presented. Water has no significant role in the coadsorption with SO2 on the two surfaces in UHV conditions.
[1] S. Oesch and M. Faller, Corrosion Science 39 (1997) 1505
[2] S. Chaturvedi, J.A. Rodriguez, T. Jirsak, J. Hrbek, J. Phys. Chem. B 102 (1998) 7033
[3] J.A. Rodriguez, T. Jirsak, S. Chaturvedi, J. Dvorak, J. of Mol. Catal. A: Chemical 167 (2001) 47 |