Nanostructured Tio.7Mo_0.3O_2 Support Enhances Electron Transfer to Pt: High-Performance Catalyst for Oxygen Reduction Reaction

摘要

The slow rate of the oxygen reduction reaction (ORR) and the instability of Pt-based catalysts are two of the most important issues that must be solved in order to make proton exchange membrane fuel cells (PEMFCs) a reality. Additionally, the serious carbon corrosion on the cathode side is a critical problem with respect to the durability of catalyst that limits its wide application. Here, we present a new approach by exploring robust noncarbon Ti_0.7Mo_0.3O_2 used as a novel functionalized cocatalytic support for Pt. This approach is based on the novel nanostructure Ti_0.7Mo_0.3O_2 support with "electronic transfer mechanism" from Ti_0.7Mo_0.3O_2 to Pt that can modify the surface electronic structure of Pt, owing to a shift in the d-band center of the surface Pt atoms. Furthermore, another benefit of Ti_0.7Mo_0.3O_2 is the extremely high stability of Ti_0.7Mo_0.3O_2during potential cycling, which is attributable to the strong metal/support interaction (SMSI) between Pt and Ti_0.7Mo_0.3O_2 This also enhances the inherent structural and chemical stability and the corrosion resistance of the TiO2-based oxide in acidic and oxidative environments. We also demonstrate that the ORR current densities generated using cocatalytic Ti_0.7Mo_0.3O_2 are respectively ~7- and 2.6-fold higher than those of commercial Pt/C and PtCo/C catalysts with the same Pt loading. This new approach opens a reliable path to the discovery advanced concept in designing new catalysts that can replace the traditional catalytic structure and motivate further research in the field.