Abstract
Photoemission of physisorbed noble gases has been used to investigate the variation of the surface potential on a potassium-promoted rhodium (111) surface. The results confirm that the predominant effect of potassium is to lower the potential on nearest neighbour sites by 1–1.5 eV, but indicate also that the potential on next nearest neighbour sites is still 0.4–1 eV lower than on unpromoted rhodium, depending on the potassium coverage. Theoretical calculations show that the latter values are in qualitative agreement with the cumulative effect of potassium/rhodium dipoles which form an ordered array on the surface.
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Janssens, T.V.W., Wandelt, K. & Niemantsverdriet, J.W. Long and short range effect of alkali promoters on metal surfaces: K on Rh(111). Catal Lett 19, 263–272 (1993). https://doi.org/10.1007/BF00771763
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DOI: https://doi.org/10.1007/BF00771763