AVS 62nd International Symposium & Exhibition
    Scanning Probe Microscopy Focus Topic Thursday Sessions
       Session SP+AS+NS+SS-ThM

Paper SP+AS+NS+SS-ThM5
Dissociation of Water on Oxygen Pre-Covered Cu(110) Observed with Scanning Tunneling Microscopy

Thursday, October 22, 2015, 9:20 am, Room 212A

Session: Probing Chemical Reactions at the Nanoscale
Presenter: Zongqiang Pang, Lawrence Berkeley National Laboratory (LBNL)
Correspondent: Click to Email
The dissociation of water on the oxygen pre-covered Cu(110) surface has been studied with Scanning Tunneling Microscopy (STM). At low temperature (77K), water reacts with pre-covered oxygen to produce hydrogen atoms and hydroxyl groups. Non-dissociated water molecules and hydroxyl groups combine to form a hexagonal network on the top of Cu(110) where water donates one hydrogen to the hydroxyl, while uncoordinated hydroxyls bind to the second layer intact water molecules. Following excitation by tunneling electron or by heat, the water molecules in the hexagonal network gradually dissociate. The oxygen atoms involved in the reaction of water dissociation return to its original position, leaving ordered Cu-O and hydroxyl dimer chains on the Cu(110) surface which both align along <001> direction. Our results demonstrate that the oxygen atoms pre-adsorbed on the Cu(110) surface lower the energy barrier for water dissociation on the Cu(110) surface.