Electron-mediated CO oxidation on the TiO2(110) surface during electronic excitation.
The role of electrons and holes in the electronically excited oxidation of adsorbed CO on TiO(2)(110) has been investigated by tuning the surface electron and hole availability by the adsorption of Cl(2) or O(2). The presence of an electron acceptor (Cl(2) or O(2)) on the TiO(2)(110) surface causes upward band bending, increasing the excited hole availability and decreasing the excited electron availability in the near surface region. This enhances O(2) desorption and depresses CO(2) production during electronic excitation. This result gives clear evidence for the first time that the electronically excited CO oxidation reaction is caused by an electron-mediated process in contrast to O(2) desorption which is mediated by holes.
Zhang
Zhen
Z
Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, USA.
Yates
John T
JT