American Chemical Society
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Design of Efficient Catalysts for CO Oxidation on Titanium Carbide-Supported Platinum via Computational Study

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journal contribution
posted on 2018-10-19, 00:00 authored by Shiyan Wang, Zongxian Yang, Xingli Chu, Weichao Wang
The formation, geometries, electronic structures, and catalytic properties of monovacancy and divacancy of the defective TiC(001) with single Pt atom and Pt dimer are systematically studied based on the first-principles calculations. Compared with the diffusion barrier of Pt1 on VC-TiC­(001), Pt2 on VC-TiC­(001) has a larger diffusion barrier, indicating that the VC-TiC­(001) substrate can stabilize the Pt dimer and inhibit its diffusion efficiently. Compared with the Pt1/VC-TiC­(001), the DOS plot of Pt2/VC-TiC­(001) presents a peak at the Fermi energy caused by variations in the electronic structure of the VC-TiC­(001)-modified outermost Pt2, which indicates that the supported Pt2 has a high activity on VC-TiC­(001). The steady Pt2/VC-TiC­(001) catalyst exhibits outstanding activity for CO oxidation in the Langmuir–Hinshelwood (LH) and termolecular Eley–Rideal (TER) mechanisms for the rate-limiting step of the OOCO and OCOOCO dissociation, having the energy barriers of 0.32 and 0.52 eV, respectively, which are both more preferable than the Eley–Rideal (ER) mechanism. Therefore, the Pt2/VC-TiC­(001) is quite efficient for CO oxidation. The existing results are expected to help us to develop efficient catalysts that are highly tolerant to CO poisoning.