Nitridated Nickel Mesh as Industrial Water and Alcohol Oxidation Catalyst: Reconstruction and Iron‐Incorporation Matters

• Published in: Advanced energy materials 2024-06, Vol.14 (22), p.n/a
• Main Authors: Ghosh, Suptish, Hausmann, Jan Niklas, Reith, Lukas, Vijaykumar, Gonela, Schmidt, Johannes, Laun, Konstantin, Berendts, Stefan, Zebger, Ingo, Driess, Matthias, Menezes, Prashanth W.
• Format: Article
• Language: English
• Subjects: Benzoic acid; Benzyl alcohol; Catalysts; Electrocatalysts; Electrodes; high current density; Industrial water; industrially relevant water splitting; Iron; Iron compounds; Nickel compounds; Oxidation; oxygen evolution reaction (OER); Oxygen evolution reactions; Potassium hydroxides; Reconstruction; selective alcohol oxidation; self‐supported nickel nitride; Substrates; Temperature dependence
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202400356

Nickel mesh (NM) is used in industrial alkaline water electrolyzers due to its cost‐effectiveness and conductivity. However, the decisive factors that advance the efficiency and sustainability of such electrodes are only partially understood. Herein, an efficient NM‐based electrocatalyst for the oxygen evolution reaction is developed via a single‐step nitridation route on a commercially used NM substrate and sheds light on the role of reconstruction and iron content to boost catalyst performance and durability. Remarkably, the activated Ni3N/NM catalyst required an overpotential of 0.46 V to deliver 1 A cm−2 in ambient conditions (1 M KOH, 25 °C). This overpotential decreases substantially to 0.28 V in industrially relevant conditions (6 M KOH, 85 °C) and is maintained for 235 h. Ni3N/NM partially transformed into NiFe layered (oxy)hydroxide in both conditions, while the active structure's Fe content is reconstruction condition dependent (temperature and KOH concentration). Electrodes reconstructed under industrially relevant conditions performed better than ambient reconstructed ones due to a more pronounced iron‐incorporation from KOH and the evolution of porous morphologies. In industrial environments, activated Ni3N/NM excels in selectively converting benzyl alcohol to benzoic acid, achieving an impressive yield of 96%. A self‐supported nickel nitride (pre)catalyst on a nickel mesh electrode (Ni3N/NM) for industrial alkaline oxygen evolution and selective oxygenation of benzyl alcohol is discovered. Its remarkable performance and durability (>235 h) along with a mere overpotential of 0.28 V at 1 A cm−2 under 6 M KOH at 85 °C is attributed to iron from KOH electrolyte transforming into Fe‐rich NiFe layered (oxy)hydroxide active catalyst.