A periodic model for the V2O5-TiO2 (anatase) catalyst. Stability of dimeric species

We present periodic DFT calculations to study the structure of the V₂O₅-TiO₂ (anatase) catalyst. Linear and cyclic dimeric V₂O₅ species represent the active phase. The support TiO₂ (anatase) is represented for the perfect (1 0 0) and (0 0 1) surfaces. The maximum interaction between the active phase and the support is favored, and low coverage is assumed. The most stable models allow the compensation of the surface dangling bonds, and can be understood as a continuation of the bulk anatase structure. The more suitable models for studying reactivity possess uncoordinated atoms available for reactivity, such as terminal oxygen atoms in V₂O₅. Relaxation plays an important role in the adsorption systems, and cannot be discarded when modeling the V₂O₅-anatase catalyst.