Adatom Extraction from Pristine Metal Terraces by Dissociative Oxygen Adsorption: Combined STM and Density Functional Theory Investigation of O/Ag(110)

作者:Pal Jagriti*; Rawal Takat B; Smerieri Marco; Hong Sampyo; Alatalo Matti; Savio Letizia; Vattuone Luca; Rahman Talat S; Rocca Mario
来源:Physical Review Letters, 2017, 118(22): 226101.
DOI:10.1103/PhysRevLett.118.226101

摘要

The reconstruction and modification of metal surfaces upon O-2 adsorption plays an important role in oxidation processes and in gauging their catalytic activity. Here, we show by employing scanning tunneling microscopy and the ab initio density functional theory that Ag atoms are extracted from pristine (110) terraces upon O-2 dissociation, resulting in vacancies and in Ag-O complexes. The substrate roughening generates undercoordinated atoms and opens pathways to the Ag subsurface layer. With increasing O coverage, multiple vacancies give rise to remarkable structures. The mechanism is expected to be very general depending on the delicate interplay of energy and entropy, so that it may be active for other materials at different temperatures.

  • 出版日期2017-6-1