Structural, morphological and electrochemical characterization of the degradation processes during the oxygen reduction reaction of iron(II) phthalocyanine supported on carbon nanotubes

• DOI: 10.1016/j.electacta.2023.142060
• Publication Date: 2023-02-15T23:28:44Z
• Authors: Simon-Johannes Ki...; Matthias Steimecke; Emil Dieterich; Michael Bron
• Keywords: Carbon fibers; Degradation

A non-noble metal catalyst (Fe-Nx@MWCNTs), which was prepared by wet impregnation of surface-functionalized multi-walled carbon nanotubes (MWCNTs) with iron(II) phthalocyanine (FePc) and heat treatment, as well the functionalized MWCNTs without FePc were examined towards their performance for oxygen reduction reaction (ORR) in neutral media structural properties during electrochemically forced degradation. Electroanalytical methods situ-Raman microscopy ex situ-X-ray photoelectron spectroscopy (XPS) applied at different levels a two-stage accelerated stress test (AST). In particular, comparability between electrochemical, situ-XPS setup confirmed. It found that iron central atom leached out Fe-Nx-complex first stage AST causing decline ORR activity, still higher than MWCNT support, remained unaffected. During second stage, samples subjected to stronger electrochemical cycling highly positive potentials, formation surface groups an increase double layer capacitance. The high potentials also destroy remaining catalytic NC moieties activity approaches bare support. With ongoing cycling, overall current is heavily reduced attributed loss electric conductivity sample backbone further oxidation.