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Characterization of hydrogen gas diffusion electrodes for reduction of metal from industrial process liquids
Author(s) -
Schulze M.,
Lorenz M.,
Wagner N.
Publication year - 2002
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.1379
Subject(s) - electrode , materials science , electrochemistry , electrolysis , galvanic cell , electrolyte , x ray photoelectron spectroscopy , chemical engineering , metal , carbon black , working electrode , scanning electron microscope , metallurgy , composite material , chemistry , natural rubber , engineering
Abstract Gas diffusion electrodes can be operated in a lot of electrochemical processes and devices, such as fuel cells, electrolysis and cleaning of waste water from electrochemical treatments of metals (electrochemical machining, electrochemical drilling and galvanic processes). Carbon black‐supported platinum is mixed with polytetrafluoroethylene (PTFE) in a knife mill and rolled onto a metal web to form an electrode. The electrodes were characterized before and after electrochemical operation with x‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Induced by the rolling process of the PTFE–carbon black powder, the PTFE forms thin fibres that are spun to a web in the electrode. The surface composition of the electrodes for electrochemical metal treatment and cleaning of galvanic waste water changes during the operation time. Owing to the presence of metal ions in the liquid electrolyte in these applications, metal is deposited onto the electrode surface during the operation time. Depth profiling of the electrodes shows that metal is not only deposited on the surface but also in the electrodes. Copyright © 2002 John Wiley & Sons, Ltd.