A DFT+U study of the catalytic degradation of 1,2-dichloroethane over CeO₂

The catalytic degradation of 1,2-dichloroethane (DCE) at CeO₂(111) was investigated using periodic density functional theory calculations corrected by on-site Coulomb interactions. From thorough calculations of possible elementary steps, we are able to identify the lowest energy reaction pathway for the catalytic oxidation of DCE at CeO₂(111). It proceeds via two successive C-Cl bond breaking processes to form adsorbed CH₂CH₂ species, and after further dehydrogenation and C-C bond scission, the surface species are finally oxidized to CO₂ and H₂O. The surface oxygen vacancies were found to be important for the catalytic decomposition of DCE, by providing the adsorption sites, as well as for charge transfer to favor C-Cl bond breaking. We are also able to illustrate the effect of H₂O on the catalytic activity of CeO₂(111) for DCE oxidation.