In this study, we performed periodic DFT calculations to clarify the interfacial properties of zirconia-supported precious metal catalyst systems. Atomic precious metals (Pt, Pd and Rh) and four-metal-atom clusters (Pt4, Pd4 and Rh4) were deposited on the ZrO2(1 1 1) surface. The Pt and Rh show much stronger interaction with the ZrO2(1 1 1) surface than the Pd, indicating that the Pt-ZrO2 and Rh-ZrO2 interfaces are energetically more stable than the corresponding Pd-ZrO2 interface. The effect of support relaxation on the adsorption energies reveals that a larger support relaxation effect can be observed on the Pt-ZrO2 interface compared to the Pd-ZrO2 interface. The Pt adsorption was associated with the largest support rearrangement with strong Pt-Zr interaction. The precious metal atoms on the ZrO2(1 1 1) surface were positively charged. The electron transferred from the precious metal to the ZrO2(1 1 1) surface was localized on the Zr atom. Moreover, electron exchanges on the Pt-ZrO2 and Rh-ZrO2 interfaces were more significant than that on the Pd-ZrO2 interface. Additionally, the oxidization effects on the interaction between the precious metals and the ZrO2 support were also investigated. The oxidization weakened the metal-metal interaction of the M4 cluster, while the metal-ZrO2 interaction was increased by the oxidization.
All Science Journal Classification (ASJC) codes
- Process Chemistry and Technology