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- Title
The Space Confinement Approach Using Hollow Graphitic Spheres to Unveil Activity and Stability of Pt-Co Nanocatalysts for PEMFC.
- Authors
Pizzutilo, Enrico; Knossalla, Johannes; Geiger, Simon; Grote, Jan‐Philipp; Polymeros, George; Baldizzone, Claudio; Mezzavilla, Stefano; Ledendecker, Marc; Mingers, Andrea; Cherevko, Serhiy; Schüth, Ferdi; Mayrhofer, Karl J. J.
- Abstract
The performance of polymer electrolyte fuel cells is strongly correlated to the electrocatalytic activity and stability. In particular, the latter is the result of an interplay between different degradation mechanisms. The essential high stability, demanded for real applications, requires the synthesis of advanced electrocatalysts that withstand the harsh operation conditions. In the first part of this study, the synthesis of oxygen reduction electrocatalysts consisting of Pt-Co (i.e., Pt5Co, Pt3Co, and PtCo) alloyed nanoparticles encapsulated in the mesoporous shell of hollow graphitic spheres (HGS) is reported. The mass activities of the activated catalysts depend on the initial alloy composition and an activity increase on the order of two to threefold, compared to pure Pt@HGS, is achieved. The key point of the second part is the investigation of the degradation of PtCo@HGS (showing the highest activity). Thanks to pore confinement, the impact of dissolution/dealloying and carbon corrosion can be studied without the interplay of other degradation mechanisms that would induce a substantial change in the particle size distribution. Therefore, impact of the upper potential limit and the scan rates on the dealloying and electrochemical surface area evolution can be examined in detail.
- Subjects
PLATINUM catalysts; PROTON exchange membrane fuel cells; ELECTROCATALYSIS; ELECTROCATALYSTS; OXYGEN reduction; MESOPOROUS materials
- Publication
Advanced Energy Materials, 2017, Vol 7, Issue 20, pn/a
- ISSN
1614-6832
- Publication type
Article
- DOI
10.1002/aenm.201700835