Reversible and Irreversible Cation Intercalation in NiFeOxOxygen Evolution Catalysts in Alkaline Media

The Journal of Physical Chemistry Letters, vol. 14, pp. 545–551

Abstract

High Resolution Image Download MS PowerPoint Slide For electrocatalysts with a layered structure, ion intercalation is a common phenomenon. Gaining reliable information about the intercalation of ions from the electrolyte is indispensable for a better understanding of the catalytic performance of these electrocatalysts. Here, we take a holistic approach for following intercalation processes by studying the dynamics of the catalyst, water molecules, and ions during intercalation using operando soft X-ray absorption spectroscopy (XAS). Sodium and oxygen K-edge and nickel L-edge spectra were used to investigate the Na + intercalation in a Ni 0.8 Fe 0.2 O x electrocatalyst during the oxygen evolution reaction (OER) in NaOH (0.1 M). The Na K-edge spectra show an irreversible intensity increase upon initial potential cycling and a reversible intensity increase at the intercalation potential, 1.45 V RHE, coinciding with an increase in the Ni oxidation state. Simultaneously, the O K-edge spectra show that the Na + intercalation does not significantly impact the hydration of the catalyst.

Authors 8

1. Hanna Trzesniowski corresponding

   Helmholtz-Zentrum Berlin für Materialien und Energie

   Affiliation as printed

   Department of Atomic-Scale Dynamics in Light-Energy Conversion, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109Berlin, Germany

2. Nipon Deka Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RALeiden, The Netherlands

3. Onno van der Heijden Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RALeiden, The Netherlands

4. Ronny Golnak

   Helmholtz-Zentrum Berlin für Materialien und Energie

   Affiliation as printed

   Department of Highly Sensitive X-Ray Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109Berlin, Germany

5. Jie Xiao

   Helmholtz-Zentrum Berlin für Materialien und Energie

   Affiliation as printed

   Department of Highly Sensitive X-Ray Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109Berlin, Germany

6. Marc T. M. Koper Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RALeiden, The Netherlands

7. Robert W. Seidel

   Helmholtz-Zentrum Berlin für Materialien und Energie

   Affiliation as printed

   Department of Atomic-Scale Dynamics in Light-Energy Conversion, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109Berlin, Germany

8. Rik Valentijn Mom corresponding Aachen

   Leiden University

   Affiliation as printed

   Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RALeiden, The Netherlands