Effects of Metal Electrode Support on the Catalytic Activity of Fe(oxy)hydroxide for the Oxygen Evolution Reaction in Alkaline Media
Abstract
FeOxHy and Fe‐containing Ni/Co oxyhydroxides are the most‐active catalysts for the oxygen evolution reaction (OER) in alkaline media. However, the activity of Fe sites appears strongly dependent on the electrode‐substrate material and/or the elemental composition of the matrix in which it is embedded. A fundamental understanding of these interactions that modulate the OER activity of FeOxHy is lacking. We report the use of cyclic voltammetry and chronopotentiometry to assess the substrate‐dependent activity of FeOxHy on a number of commonly used electrode substrates, including Au, Pt, Pd, Cu, and C. We also evaluate the OER activity and Tafel behavior of these metallic substrates in 1 M KOH aqueous solution with Fe3+ and other electrolyte impurities. We find that the OER activity of FeOxHy varies by substrate in the order Au>Pd≈Pt≈Cu>C. The trend may be caused by differences in the adsorption strength of the Fe oxo ion on the substrate, where a stronger adhesion results in more adsorbed Fe at the interface during steady‐state OER and possibly a decreased charge‐transfer resistance at the FeOxHy‐substrate interface. These results suggest that the local atomic and electronic structure of [FeO6] units play an important role in catalysis of the OER as the activity can be tuned substantially by substrate interactions.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 08, 2019
- Source ID
- 10.1002/cphc.201900511
Entities
People
- Ashlee E. Vise
- Lisa J. Enman
- Michaela Burke Stevens
- Shannon W. Boettcher
Organizations
- Air Force Research Laboratory
- National Science Foundation
- Oregon Nanoscience and Microtechnologies Institute
- University of Oregon