TY - JOUR
T1 - Insights into the electronic structure of Fe penta-coordinated complexes. Spectroscopic examination and electrochemical analysis for the oxygen reduction and oxygen evolution reactions
AU - Loyola, César Zúñiga
AU - Abarca, Gabriel
AU - Ureta-Zañartu, Soledad
AU - Aliaga, Carolina
AU - Zagal, Jose H.
AU - Sougrati, Moulay Tahar
AU - Jaouen, Frédéric
AU - Orellana, Walter
AU - Tasca, Federico
N1 - Publisher Copyright:
© The Royal Society of Chemistry 2021.
PY - 2021/11/14
Y1 - 2021/11/14
N2 - Fe phthalocyanine was coordinated to pyridine-modified carbon nanotubes and studied as a catalyst for the oxygen reduction (ORR) and oxygen evolution reactions (OER). X-ray photoelectron spectroscopy (XPS), Mössbauer, and electron paramagnetic resonance spectroscopy (EPR) analysis supported that pyridine acts as an axial ligand to yield penta-coordinated catalytic active Fe sites. The impedance analyses show an increase in the double-layer capacitance (Cdl) value, corroborating the adsorption of the complexes to give FePc-Py-CNT. The evaluation of the electrocatalytic activity for the ORR was performed in both acid (0.1 M H2SO4) and basic (0.1 M KOH) media, while the evaluation of the OER activity was investigated only in alkaline medium. DFT studies revealed an increased length in the Fe-N binding of the pentacoordinate Fe-based site, leading to a decreased O2-Fe binding energy, explaining the higher ORR and OER activity of FePc-Py-CNT relative to FePc-CNT.
AB - Fe phthalocyanine was coordinated to pyridine-modified carbon nanotubes and studied as a catalyst for the oxygen reduction (ORR) and oxygen evolution reactions (OER). X-ray photoelectron spectroscopy (XPS), Mössbauer, and electron paramagnetic resonance spectroscopy (EPR) analysis supported that pyridine acts as an axial ligand to yield penta-coordinated catalytic active Fe sites. The impedance analyses show an increase in the double-layer capacitance (Cdl) value, corroborating the adsorption of the complexes to give FePc-Py-CNT. The evaluation of the electrocatalytic activity for the ORR was performed in both acid (0.1 M H2SO4) and basic (0.1 M KOH) media, while the evaluation of the OER activity was investigated only in alkaline medium. DFT studies revealed an increased length in the Fe-N binding of the pentacoordinate Fe-based site, leading to a decreased O2-Fe binding energy, explaining the higher ORR and OER activity of FePc-Py-CNT relative to FePc-CNT.
UR - http://www.scopus.com/inward/record.url?scp=85118640343&partnerID=8YFLogxK
U2 - 10.1039/d1ta05991b
DO - 10.1039/d1ta05991b
M3 - Article
AN - SCOPUS:85118640343
SN - 2050-7488
VL - 9
SP - 23802
EP - 23816
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
IS - 42
ER -
