Effect of Bimetallic Dimer-Embedded TiO(101) Surface on CO Reduction: The First-Principles Calculation.

The first-principles calculation was used to explore the effect of a bimetallic dimer-embedded anatase TiO(101) surface on CO reduction behaviors. For the dimer-embedded anatase TiO(101) surface, Zn-Cu, Zn-Pt, and Zn-Pd dimer interstitials could stably stay on the TiO(101) surface with a binding energy of about -2.36 eV, as well as the electronic states' results. Meanwhile, the results of adsorption energy, structure parameters, and electronic states indicated that CO was first physically and then chemically adsorbed much more stably on these three kinds of dimer-embedded TiO(101) substrate with a small barrier energy of 0.03 eV, 0.23 eV, and 0.12 eV. Regarding the reduction process, the highest-energy barriers of the CO molecule on the Zn-Cu dimer-embedded TiO(101) substrate was 0.31 eV, which largely benefited the CO-reduction reaction (CORR) activity and was much lower than that of the other two kinds of Zn-Pt and Cu-Pt dimer-TiO systems. Simultaneously, the products CO* and O of CO reduction were firmly adsorbed on the dimer-embedded TiO(101) surface. Our results indicated that a non-noble Zn-Cu dimer might be a more suitable and economical choice, which might theoretically promote the designation of high CORR performance on TiO catalysts.