Revitalizing Oxygen Reduction Reactivity of Composite Oxide Electrodes via Electrochemically Deposited PrOx Nanocatalysts

• Published in: Advanced materials (Weinheim) 2024-06, Vol.36 (25), p.e2307286-n/a
• Main Authors: Nam, Seongwoo, Kim, Jinwook, Kim, Hyunseung, Ahn, Sejong, Jeon, SungHyun, Choi, Yoonseok, Park, Beom‐Kyeong, Jung, WooChul
• Format: Article
• Language: English
• Subjects: (cathodic) electrochemical deposition; all‐ceramic electrodes; Ambient temperature; Chemical reduction; composite oxide electrodes; Electrode polarization; Electrodes; Heat treatment; Lanthanum; Oxygen reduction reactions; Solid oxide fuel cells; transmission line model; Transmission lines; Yttria-stabilized zirconia; Yttrium oxide; Zirconium dioxide
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202307286

Solid oxide fuel cells that operate at intermediate temperatures require efficient catalysts to enhance the inherently poor electrochemical activity of the composite electrodes. Here, a simple and practical electrochemical deposition method is presented for fabricating a PrOx overlayer on lanthanum strontium manganite–yttria‐stabilized zirconia (LSM–YSZ) composite electrodes. The method requires less than four minutes for completion and can be carried out under at ambient temperature and pressure. Crucially, the treatment significantly improves the electrode's performance without requiring heat treatment or other supplementary processes. The PrOx‐coated LSM–YSZ electrode exhibits an 89% decrease in polarization resistance at 650 °C (compared to an untreated electrode), maintaining a tenfold reduction after ≈400 h. Transmission line model analysis using impedance spectra confirms how PrOx coating improved the oxygen reduction reaction activity. Further, tests with anode‐supported single cells reveal an outstanding peak power density compared to those of other LSM–YSZ‐based cathodes (e.g., 418 mW cm−2 at 650 °C). Furthermore, it is demonstrated that multicomponent coating, such as (Pr,Ce)Ox, can also be obtained with this method. Overall, the observations offer a promising route for the development of high‐performance solid oxide fuel cells. Presents a concise, straightforward approach and mechanistic insight that enables high activity in all‐ceramic electrodes, providing both industrial and academic value. An old‐fashioned composite oxide cathode (i.e., LSM–YSZ) in which a Pr‐based nanocatalyst is introduced using an ‘electrochemical deposition approach’ shows reinvigorated electrochemical performance, shedding new light on its potential as an air electrode.