Design of Ni-coordinated MOF on stainless steel via electrodeposition as efficient and stable oxygen evolution electrode for alkaline water electrolysis

Ni-succinate/tartrate metal-organic framework (MOF) structures were synthesized on 304 stainless steel (SS) mesh by electrodeposition to prepare porous electrodes for oxygen evolution reaction (OER) in alkaline conditions. Morphological and compositional studies confirmed the synthesis of Ni-coordinated MOF nanoparticles onto the SS mesh. Succinate and tartrate-based MOFs were successfully tested as electrocatalysts for OER in 1 M KOH solution in both batch and flow-through cell configurations, assessing a low Tafel slope value of 46 mV dec−1 and overpotential value at 10 mA cm−2 of 326 mV. These electrodes further showed high electrocatalytic durability in a 100 h stability test at 50 mA cm−2. The stability test was carried out in both 1 M KOH and in 6 M KOH aqueous solution, being the latter close to the real electrolyte composition of industrial alkaline electrolyzers, proving an outstanding electrocatalytic durability. Theoretical analysis helped in understanding reaction mechanism depending on the nature of the active phase. This study shows a valuable approach for designing platinum group metals (PGMs) and critical raw materials (CRMs)-free electrodes for industrial alkaline water electrolysis.