Incorporation of alkali metals on Pt(111)

Abstract
The alkali-metal-doped platinum (111) surface is one of the most popular model systems for studies on catalytic promotion. Our results indicate that in the low-coverage range the alkali metals Na and K are incorporated into the surface. This is in contrast to the widely accepted adsorption geometry and calls for the reexamination of the current picture of alkali-metal-coadsorbate interactions on Pt(111). The driving mechanism for the incorporation is apparently different from that known on other metal surfaces and may be related to the large surface stress of Pt(111).