Coupling Pd nanoparticles on fine Ti 4 O 7 with oxygen vacanciesas a high-activity, long-life ORR electrocatalyst

In this work, fine Ti 4 O 7 powders with many defects were prepared by ball milling and sonication treatments and used as a support material to load Pd nano-particles (Pd NPs). The electrocatalytic performance of this catalyst (Pd/Ti 4 O 7 (F)) towards oxygen reduction reaction (ORR) was investigated. It was found that as compared with Pd NPs supported on commercial Ti 4 O 7 (Pd/Ti 4 O 7 (C)), Pd/C, and commercial Pt/C, the Pd/Ti 4 O 7 (F) catalyst exhibited the best catalytic activity and excellent durability in alkaline solution. According to X-ray photoelectron spectra (XPS), electron paramagnetic resonance (EPR) spectra, and conductivity measurement results, the strong metal-support interactions (SMSIs) and high conductivity induced by abundant oxygen vacancies and disorder layers in the treated Ti 4 O 7 support play a vital role in promoting the ORR activity of this electrocatalyst. These provide a new strategy for the design of high-performance ORR catalysts.