Phosphorus adlayers on Platinum (110)

Platinum is a metal utilized in many applications. Its catalytic activity can be decreased due to chemical poisoning caused e.g. by phosphorus. To gain more understanding of its poisoning, we present a study of phosphorus adsorption on a platinum (110) single crystal surface. Using X-ray photoelectron spectroscopy, we have found that the adsorbate coverage saturates at around 3 monolayers. Annealing the phosphorus-covered platinum surface at 750 °C gives rise to three different ordered adlayer structures, with symmetries of 2 × 3, 11 × 4 and 2×1 from the lowest to the highest coverage, detected with low-energy electron diffraction. We have studied the sample topography with scanning tunnelling microscopy. We also present a tentative model for the observed structures and their evolution.