(339b) Enhancing ORR Activity and Durability Via Employing TiO2-Based Supports for Pt Nanoparticles

It is still a challenging issue for the commercialization of the fuel cell to improve the sluggish oxygen reduction reaction (ORR) kinetics and the durability under corrosive ORR condition for cathode electrocatalysts. In this study, we report a promising approach to address these two major issues; the Cr doping to TiO2 supports for Pt-based electrocatalysts. It was clearly revealed that the Cr doping led to a marked enhancement of ORR kinetics which was attributed to the compressive strain in the Pt lattice as well as the increased electronic conductivity of the Cr-TiO₂ supports. Furthermore, Pt/Cr-TiO₂ demonstrated a far superior durability to the conventional Pt/C which was assessed by the accelerated durability tests (ADT) and the in-situ XANES studies. While the specific activity for Pt/C was decreased by 43% (141 μA/cm² and 82 μA/cm², for before and after ADT, respectively) after ADT, that for Pt/Cr-TiO₂ was merely reduced by 13% (472 μA/cm² and 409 μA/cm²).