Nitrogen doped titania stabilized Pt/C catalyst via selective atomic layer deposition for fuel cell oxygen reduction.

To effectively solve the electrochemical degradation problem of commercial Pt/C catalyst in fuel cell, nitrogen doped titania oxynitride (N-TiO 2) decorated Pt low-coordinated sites on a commercial Pt/C catalyst is achieved by coupling single-cycle selective atomic layer deposition of TiO 2 and following nitriding process that exhibits outstanding durability enhancement without changing the size distribution and wasting the electrochemical active area of Pt. [Display omitted] • TiO 2 was selectively decorated on Pt nanoparticles by atomic layer deposition. • The nitridation of TiO 2 stabilized the defect sites on Pt nanoparticles. • N-doped TiO 2 kept the exposure of Pt nanoparticles active sites. • N-doped TiO 2 decorated Pt/C showed durability promotion in fuel cell. The electrochemical dissolution of platinum (Pt) based nanoparticles and the consequent Pt active sites losses and particle aggregation have become a critical stability issue for the commercial proton exchange membrane fuel cell. Herein, nitrogen doped titania (N-TiO 2) stabilized Pt low-coordinated sites on a commercial Pt/C catalyst is achieved by simply coupling selective atomic layer deposition of TiO 2 and following nitrogen doping process. Selectively deposited N-TiO 2 on Pt nanoparticles keeps the exposure of Pt sites on (111) facets and increases the reduction states of Pt, which results in 1.7 times improvement of mass activity than commercial Pt/C. Besides, N-TiO 2 stabilized commercial Pt/C catalyst exhibits outstanding durability enhancement, showing only a 14.0% loss of mass activity after 30,000 potential cycles of rotating disk electrode tests and 91.7% retention after durability tests in humid fuel cell condition. The shielding role of N-TiO 2 could effectively inhibit the degradation of low-coordinated sites on Pt nanoparticles and maintain Pt size distribution, which is a promising strategy to prolong the lifetime of commercial Pt/C catalysts. [ABSTRACT FROM AUTHOR]