Formation of a Chemisorbed Water-Hydroxyl Phase on Cu(110) Mediated by Surface Transport.

Under ambient conditions, most of the solid surfaces are commonly covered with water and oxygen both playing a crucial role in catalysis, corrosion, and electrochemistry. We present an STM study on water interaction with the oxygen preadsorbed Cu(110)-(2 × 1)-O surface. Under water adsorption at ∼200 K, the (2 × 1) added-on Cu–O chains are gradually transformed into mobile copper-hydroxyls complexes. Long-range transport and condensation of the complexes induce nucleation and growth of 2D copper islands. Simultaneously the associated hydroxyls self-assemble with oncoming water molecules into a well-ordered 2D water-hydroxyl chemisorbed phase thermally stable up to a room temperature. We found that the assembly of the water-hydroxyl phase could be consistently described in terms of H bonds formation between the adsorbate species. We anticipate that the understanding of the forces driving the chemisorption will stimulate studies on water chemisorption on other metal surfaces, which are still far from being ...