Cobalt–Iron (Oxy)hydroxide Oxygen Evolution Electrocatalysts: The Role of Structure and Composition on Activity, Stability, and Mechanism

Cobalt oxides and (oxy)hydroxides have been widely studied as electrocatalysts for the oxygen evolution reaction (OER). For related Ni-based materials, the addition of Fe dramatically enhances OER activity. The role of Fe in Co-based materials is not well-documented. We show that the intrinsic OER activity of Co(1-x)Fe(x)(OOH) is ∼100-fold higher for x ≈ 0.6-0.7 than for x = 0 on a per-metal turnover frequency basis. Fe-free CoOOH absorbs Fe from electrolyte impurities if the electrolyte is not rigorously purified. Fe incorporation and increased activity correlate with an anodic shift in the nominally Co(2+/3+) redox wave, indicating strong electronic interactions between the two elements and likely…

• RC
  Research Corporation for Science Advancement
• DO
  Division of Chemistry

  Award: CHE-1301461