Pyrolysis-free Fe–PIPhen catalyzes alkaline ORR
An Fe2+ coordination polymer of a nitrogen-rich phenanthroline ligand on carbon reduces O2 near 0.85 V with a four-electron pathway.
Source
Supramolecular Iron Complex Formed Between Nitrogen Riched Phenanthroline Derivative and Iron With Improved Oxygen Reduction Activity in Alkaline Electrolyte
What they did
Authors condensed phenanthroline-dione with bipyridyl-dialdehyde to PIPhen, coordinated Fe2+, loaded Vulcan XC-72 without pyrolysis, and ran RRDE/XPS/XRD.
What they found
Onset ~0.85 V; average electron number 3.94 at 1600 rpm; H2O2 yield 1.6–3.1%; k1 ≫ k2 ≈ k3 (k1/k2 = 30–50). XPS: 0.748 at% Fe.
The limits
What it doesn't show
No PEMFC device data; alkaline-only; Fe loading is low and part of the polymer is microcrystalline.
Key terms
- ORR
- Oxygen reduction reaction, ideally O2 + 4H+ + 4e– → 2H2O (or alkaline analogue).
- PIPhen
- Nitrogen-rich phenanthroline–imidazole ligand made by condensation.
- RRDE
- Rotating ring–disk electrode used to quantify H2O2 and electron number.
- Four-electron pathway
- Direct reduction of O2 to water rather than peroxide.
- Pyrolysis-free M–N–C
- ORR catalyst that keeps a molecular Fe–N coordination polymer instead of high-T carbonization.
Flashcards
Research intelligence for this paper
See its role on concept claims, tensions it is part of, placement history, and related discoveries.
Quiz yourself
Fe-PIPhen/C is made:
Common questions
Was the catalyst pyrolyzed?
No—Fe-PIPhen was loaded on carbon powder only.
Onset potential?
About 0.85 V, slightly below Pt/C.
Electron number?
Average n = 3.94.
Main kinetic path?
k1 (4e– to water) is 30–50× k2 (peroxide).
More on Electrochemistry