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Thin‐Film Electrodes: Microscopic and Nanoscopic Three‐Phase‐Boundaries of Platinum Thin Film Electrodes on YSZ Electrolyte (Adv. Funct. Mater. 3/2011)
Author(s) -
Ryll Thomas,
Galinski Henning,
Schlagenhauf Lukas,
Elser Pierre,
Rupp Jennifer L. M.,
BieberleHutter Anja,
Gauckler Ludwig J.
Publication year - 2011
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201190000
Subject(s) - materials science , electrode , yttria stabilized zirconia , thin film , grain boundary , electrolyte , nanoscopic scale , electrochemistry , platinum , oxide , nanotechnology , composite material , cubic zirconia , chemical engineering , microstructure , metallurgy , ceramic , catalysis , biochemistry , chemistry , engineering
Agglomerated Pt thin films have been proposed as electrodes for electrochemical devices like micro‐solid oxide fuel cells (μ‐SOFCs) operating at low temperatures. However, comprehensive studies elucidating the interplay between agglomeration state and electrochemical properties are lacking. In this contribution the electrochemical performance of agglomerated and “dense” Pt thin film electrodes on yttria‐stabilized‐zirconia (YSZ) is correlated with their microstructural characteristics. Besides the microscopically measurable triple‐phase‐boundary (tpb) where Pt, YSZ and air are in contact, a considerable contribution of “nanoscopic” tpbs to the electrode conductivity resulting from oxygen permeable grain boundaries is identified. It is demonstrated that “dense” Pt thin films are excellent electrodes provided their grain size and thickness are in the nanometer range. The results disprove the prevailing idea that the performance of Pt thin film electrodes results from microscopic and geometrically measurable tpbs only.