Cobalt-based dual ligand metal organic framework as bifunctional electrocatalyst for value-added hydrogen production in iodide-containing water electrolysis
Year: 2026
Type: article
Abstract: Replacing the sluggish anodic oxygen evolution reaction (OER) with the thermodynamically favorable iodide oxidation reaction (IOR, 0.46 V ) represents a promising strategy to reduce energy consumption in hydrogen-producing water electrolysis. Herein, a highly efficient, noble-metal-free bifunctional electrocatalyst is developed by synthesizing a dual-ligand cobalt-based metal-organic framework (Co-TD) directly on nickel foam via a solvothermal method. By simultaneously introducing terephthalic acid (H 2 BDC) and trimesic acid (H 3 BTC), the synergistic dual-ligand effects successfully regulate the local coordination environment and electronic structure around Co centers, while optimizing the porous surface morphology. Electrochemical assessments in 1.0 M KOH + 0.5 M KI demonstrate that Co-TD exhibits exceptional bifunctional catalytic activity. In a two-electrode overall electrolysis system, Co-TD requires an operating voltage of only 1.61 V to achieve 100 mA cm −2 , outperforming its single-ligand counterparts (Co-BDC and Co-BTC) and yielding a high hydrogen Faradaic efficiency of 98.6%. Crucially, chronopotentiometry confirms outstanding operational durability, maintaining stable performance at 100 mA cm −2 for ~455 h. In-operando Raman spectroscopy reveals a dynamic, potential-dependent, and partially reversible surface reconstruction into CoOOH-related during IOR. Post-reaction characterizations confirm that Co-TD effectively preserves its hierarchical nanostructure and structural integrity after rigorous electrochemical testing. This work demonstrates that the dual-ligand design strategy coupled with alternative anode oxidation provides a viable approach for energy-efficient green hydrogen production.
Source: Electrochemistry Communications
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,630
OpenAlex ID: W7223663749