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

Abstract

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%.

4d-Metal Ion Ru3+-Incorporation in Prussian Blue Analogue-Derived Anodic NiFe(O)OH and Cathodic NiFe(OH)2 Nanosheets Promotes Electrochemical Seawater Splitting

“…After 100 h of CA stability for overall seawater splitting, we carried out Raman spectroscopy to detect changes in the active catalysts. The Raman spectra of Ru–NiFe­(O)­OH before the stability test indicated the peaks at 464, 508, and 534 cm –1 for the δ­(Ni III –OO), v (Ru III –O), and ν­(Fe III –O) bands, respectively. , After the CA test, a positive shift of ∼6 cm –1 was observed toward a higher value compared to that of the fresh catalyst (Figure S25). Furthermore, Raman spectra of Ru–NiFe­(OH) 2 before the stability test showed peaks at 473, 503, and 551 cm –1 for δ­(Ni II –O), v (Ru III –O), and ν­(Fe II –O) bands, respectively.…”

“…After the CA test, a positive shift of ∼4 cm –1 was observed toward a higher value compared to that of the fresh catalyst (Figure S26). , …”

Deciphering the Role of Nickel in Electrochemical Organic Oxidation Reactions

“…[144] 2) Most of the electrochemical oxidation processes are reported only based on alcohols, amines, urea, ammonia, and biomass (HMF) hydroxylation or dehydrogenation. Moreover, the reaction conditions, [145] chemical additives, and suitable organic substrate are also little known to get oxidative coupling reactions. The limitation in substrate scope is partly attributed to the use of an aqueous (particularly alkaline) reaction medium, restricting solubility for a broader range of organic compounds.…”

“…A recent advancement to implement industrialrelevant conditions (≥6 m KOH, ≥65 °C) is often used to test the OER activity for the mass production of H 2 and decrease the overall cell potential (as a function of temperature) of overall water electrolysis, which has not been explored extensively for OORs. [145] Knowing that the yield and selectivity of the OORs are largely dependent on temperature and solvent conditions, it can suitably be coupled with industrial-relevant OER conditions attributing to great industrial importance. 7) Product purification from the electrolyte solution must be more simplified and should run under low-cost operating techniques.…”

Metal–organic frameworks (MOFs) for hybrid water electrolysis: structure–property–performance correlation

“…49–52 In comparison to traditional catalysts, MOFs offer the significant potential improvements, including higher conversion rates and selectivity, excellent faradaic efficiency, increased hydrogen production, and larger current densities. 50,56–59…”