Pyrolysis of an amorphous cobalt(II) cubane-like coordination polymer towards tunable structurally disordered
Sara Frank1, Mads Folkjær1, Melissa J Marks1
1Department of Biological and Chemical Engineering, Aarhus University, Åbogade 40, 8200 Aarhus N, Denmark.
Dalton Transactions (Cambridge, England : 2003)
|May 1, 2026
Summary
Controlled pyrolysis of cobalt coordination polymers (CPs) yields tunable nanomaterials. Mild heating forms cobalt clusters with enhanced oxygen evolution reaction (OER) activity, while heavy heating leads to nanoparticle growth and reduced performance.
Area of Science:
- Materials Science
- Nanotechnology
- Catalysis
Background:
- Coordination polymers (CPs) are versatile precursors for functional nanomaterials.
- Understanding the structural evolution of CPs during pyrolysis is crucial for property tuning.
Purpose of the Study:
- To investigate the structural transformation of an amorphous cobalt(II) cubane-like CP during pyrolysis.
- To correlate structural changes with catalytic activity, specifically the oxygen evolution reaction (OER).
Main Methods:
- Pyrolysis of a cobalt(II) cubane-like CP, [Co4L4(bdc)](bdc).
- Analysis using total scattering and pair distribution function analysis (TS/PDF) and X-ray absorption spectroscopy (XAS).
- In situ XAS for real-time structural monitoring and electrochemical screening for OER activity.
Main Results:
- Two pyrolysis regimes identified: 'mild' (≤500 °C) and 'heavy' (>500 °C).
- 'Mild pyrolysis' yields distorted cobalt clusters with contracted bonds and partial ligand loss.
- 'Heavy pyrolysis' results in disordered metallic cobalt and cobalt oxide nanoparticles; OER activity is highest for 'mildly pyrolyzed' samples.
Conclusions:
- Controlled pyrolysis enables tailoring of amorphous CPs into nanomaterials with specific structures and catalytic properties.
- Optimized pyrolysis conditions are key to maximizing catalytic performance, as excessive heating can lead to detrimental agglomeration.
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