Julia Linke¹, Thomas Rohrbach¹, Adam Hugh Clark², Camelia Borca², Thomas Huthwelker², Fabian Luca Buchauer³, Mikkel Rykær Kraglund³, Christodoulos Chatzichristodoulou³, Eibhlin Meade¹, Julie Guehl¹, Mateusz Wojtas¹, Marco Ranocchiari¹, Thomas Justus Schmidt^1,4, Emiliana Fabbri^1*

1 PSI Center for Energy and Environmental Sciences, 5232 Villigen PSI, Switzerland

2 PSI Center for Photon Science, 5232 Villigen PSI, Switzerland

3 Department of Energy Conversion and Storage, Technical University of Denmark, Kongens Lyngby, Denmark

4 Institute of Molecular Physical Science, ETH Zürich, 8093 Zürich, Switzerland

* Corresponding authors emails: emiliana.fabbri@psi.ch

DOI10.24435/materialscloud:q2-rd [version v1]

Publication date: Oct 09, 2024

How to cite this record

Julia Linke, Thomas Rohrbach, Adam Hugh Clark, Camelia Borca, Thomas Huthwelker, Fabian Luca Buchauer, Mikkel Rykær Kraglund, Christodoulos Chatzichristodoulou, Eibhlin Meade, Julie Guehl, Mateusz Wojtas, Marco Ranocchiari, Thomas Justus Schmidt, Emiliana Fabbri, Revising known concepts for novel applications: Fe incorporation into Ni-MOF-74 derived oxygen evolution electrocatalysts for anion exchange membrane water electrolysis, Materials Cloud Archive 2024.151 (2024), https://doi.org/10.24435/materialscloud:q2-rd

Description

The performance of Ni-based oxygen evolution reaction (OER) electrocatalysts is enhanced upon Fe incorporation into the structure or Fe uptake from the electrolyte. In light of the promising potential of metal-organic framework (MOF) electrocatalysts for water splitting, Ni-MOF-74 is used as a model catalyst to study the effect of Fe incorporation from KOH electrolyte on the electrocatalyst’s OER activity and stability. The insights obtained from X-ray diffraction and operando X-ray absorption spectroscopy characterizations of Ni-MOF-74 and an amorphous Ni metal organic compound (Ni-MOC*) reveal that Fe uptake enhances OER by two processes: higher Ni oxidation states and enhanced flexibility of the electronic state and local structure when cycling the potential below and above the OER onset. To demonstrate the impressive OER activity and stability in Fe containing KOH, an Ni-MOC* anode was implemented in an anion exchange membrane water electrolyzer (AEM-WE) with 3 ppm Fe containing 1 M KOH electrolyte resulting in an outstanding cell voltage of 1.7 V (at an anode potential of 1.51 V) at 60 °C and 0.5 A cm-2 exceeding 130 h of stable continuous operation.

Materials Cloud sections using this data

Files

File name	Size	Description
Figure 1.zip MD5md5:8ab488df6cfad6dcd3788668b8eab4e4	72.1 KiB	OER performance of Ni-MOF-74 and its Fe uptake from Fe-containing 0.1 M KOH
Figure 2.zip MD5md5:875ba427cd29ebb235d6a7eaadfa46b9	263.2 KiB	Ex situ XRD and operando hXAS measurements of Ni-MOF-74 in Fe-free and 5 ppm Fe contaminated 0.1 M KOH electrolyte
Figure 3.zip MD5md5:bf5d3e13c57bf2683d54e18359abf5f9	69.2 KiB	Activity and Stability of Ni-MOC* upon Fe incorporation from Fe-containing 0.1 M KOH electrolyte
Figure 4.zip MD5md5:bc9d5f65c15b9259880aad50823353e8	123.3 KiB	Operando hXAS measurements of Ni K edge of Ni-MOC* during OER in clean and 5 ppm Fe contaminated 0.1 M KOH
Figure 5.zip MD5md5:5a11475e29d240ba40df3d04baacbac1	8.1 MiB	Performance of Ni-MOC* anode in AEM-WE in Fe-free and 3 ppm Fe contaminated 1 M KOH

License

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External references

Keywords

OER MARVEL electrocatalysis Ni-MOF-74 alkaline/AEM water electrolysis operando XAS/XRD Fe effect on Ni-based OER catalysts