Electron-induced dissociation of CO2 on TiO2(110).

The electron-induced dissociation of CO(2) adsorbed at the oxygen vacancy defect on the TiO(2)(110) surface has been investigated at the single-molecular level using scanning tunneling microscopy (STM). Electron injection from the STM tip into the adsorbed CO(2) induces the dissociation of CO(2). The oxygen vacancy defect is found to be healed by the oxygen atom released during the dissociation process. Statistical analysis shows that the dissociation of CO(2) is one-electron process. The bias-dependent dissociation yield reveals that the threshold energy for electron-induced dissociation of CO(2) is 1.4 eV above the conduction-band minimum of TiO(2). The formation of a transient negative ion by the injected electron is considered to be the key process in CO(2) dissociation.