Hatem Al-Mutairi

Energy Transition Specialization · Cohort 2026

Comparative Investigation of Zeolitic imidazolate frameworks(ZIF)-Derived Electrocatalysts for Oxygen and Urea Oxidation Reactions

Developing efficient anodic electrocatalysts is essential for reducing the energy consumption of electrochemical hydrogen production, while replacing the sluggish oxygen evolution reaction (OER) with thermodynamically favourable small-molecule oxidation provides a promising route toward more energy-efficient electrolysis. Here, we present a comparative investigation of ZIF-based electrocatalysts for oxygen and urea oxidation reactions (UOR), in which ZIF-8 and ZIF-67 electrodes are systematically benchmarked against Ni foam under alkaline conditions. The electrocatalytic activity, reaction kinetics, and interfacial charge-transfer behaviour were evaluated using cyclic voltammetry, linear sweep voltammetry, Tafel analysis, and electrochemical impedance spectroscopy in 1 M KOH with and without urea. In pure KOH, Ni foam exhibited an overpotential of 316 mV at 10 mA, compared with 164 mV for ZIF-8 and 369 mV for ZIF-67, although the apparent low-potential response of the ZIF-based electrodes requires careful interpretation because of capacitive and surface-redox contributions. Upon introducing urea, the anodic oxidation potentials decreased substantially, with ZIF-67 requiring only 146 mV at 10 mA, compared with 205 mV for Ni foam and 224 mV for ZIF-8. Tafel analysis further revealed slopes of 24, 82, and 90 mV dec-1 for Ni foam, ZIF-8, and ZIF-67, respectively, under UOR conditions, demonstrating distinctly different reaction kinetics among the electrodes. Overall, this comparative study highlights the strong influence of the metal centre and electrochemically reconstructed surface on alkaline OER/UOR behaviour and establishes a basis for the rational development of MOF-derived electrocatalysts for energy-saving hydrogen production.

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