2-Dimensional atomic arrangements of Te on Pt(111) whose coverage is higher than 0.25+

Presented is an in-situ electrochemical STM study on the structural evolution of Te layer on Pt(111) whose coverage is higher than 0.25. The irreversibly adsorbed oxygenated Te layer was reduced to a rectangular (2×3) adlayer of elemental Te (_Te=0.25). As additional Te was deposited underpotentially onto the Te-covered Pt(111) surface in a TeO₂-saturated 0.05 M H₂SO₄ solution, the surface structure of Te evolved from the rectangular (2×3) (_Te=0.25) to a rectangular c(2×3) (_Te=0.50) via a rectangular c(3×3) (_Te=0.33). The adsorbed elemental Te was mobile enough to compress the superlattice structure to denser ones, so that the resulting Te layer became electrochemically inactive in the potential range below 0.55 V.Dedicated to Professor György Horányi, Hungary, on the occasion of his 70th birthday.