Enhanced oxygen reduction reaction stability on platinum nanoparticles photo-deposited onto oxide-carbon composites

Oxide-Carbon composites (TiO2-C) and yttrium-doped TiO2-C (Y:TiO2-C), synthesized via sol-gel route, were used as supports to photo-deposit platinum nanoparticles (Pt NPs). The physical-chemical properties of these materials were investigated by Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD). The TEM images showed that Pt NPs were agglomerated and deposited onto oxide sites of the composites. Pt face-centered cubic, and TiO2 Anatase phases were identified on both Pt/TiO2-C and Pt/Y:TiO2-C samples. The particle size, stacking fault and micro-strain of Pt NPs were estimated by Williamson Hall method. Compared with Pt/TiO2-C, similar stacking faults as well as increased crystallite sizes and micro-strain values could be observed for Pt/Y:TiO2-C sample, indicating a minimum impact of the rare earth element on Pt. Pt/C was prepared by the same method, and used as a reference catalyst. The strong-metal/support interaction (SMSI) effect induced by the photo-deposition method, in Pt/TiO2-C and Pt/Y:TiO2-C samples, was probed by CO-stripping, and associated to the enhanced stability toward the oxygen reduction reaction (ORR) in acid medium. (C) 2016 Elsevier B.V. All rights reserved.