Sulfide interlayered cobalt-based oxynitrides for efficient oxygen evolution reaction in neutral pH water and seawater

<p dir="ltr">Sluggish kinetics of the anodic oxygen evolution reaction (OER) and minor upstream upsets in feed water quality remain bottlenecks for efficient water electrolysis, which is exacerbated under near-neutral pH environments due to H2O dissociation. In this work, we report the introduction of a NiSx interlayer in a Co-(NiFe) oxide/nitride catalyst on nickel foam substrate. Postmortem OER characterization in neutral pH synthetic seawater (SSW) shows that stable cationic [Co-(NiFe)]δ+ and anionic [O-N]δ– surface species coupled with the NiSx interlayer accelerate H₂O dissociation, thereby enhancing activity and kinetics. The electrocatalysts exhibit stable performance at 100 mA cm−2 for 50 h in alkaline and neutral pH SSW with 350 and 425 mV of overpotential, respectively. The faradaic efficiency of the NiSx interlayer catalysts is enhanced by 10.3% and 8.5% achieving 94.5% and 87.4% under alkaline and neutral pH SSW, respectively, during chronoamperometry tests at a high applied voltage of 1.75 V (vs. RHE).</p><h2>Other Information</h2><p dir="ltr">Published in: Applied Catalysis B: Environmental<br>License: <a href="http://creativecommons.org/licenses/by/4.0/" target="_blank">http://creativecommons.org/licenses/by/4.0/</a><br>See article on publisher's website: <a href="https://dx.doi.org/10.1016/j.apcatb.2023.122599" target="_blank">https://dx.doi.org/10.1016/j.apcatb.2023.122599</a></p><p dir="ltr">Additional institutions affiliated with: Chemical Engineering Program - TAMUQ</p>