Magnetic nanoparticles@Metal-organic framework composites as sustainable electrocatalyst for oxygen evolution reactions

Developing a high-performance and environmentally friendly catalyst for the oxygen evolution reaction (OER) is essential for addressing the challenges of oxygen production via water electrolysis. However, this process continues to encounter low energy efficiency due to sluggish kinetics. Herein, a metal-organic framework (MOF)-based material was designed to catalyze the slow OER. The efficacy of magnetic MOFs was demonstrated through the controlled reconstruction of lanthanide-doped Ln/Fe 3 O 4 @(MIL-53(Fe)) (where Ln = La, Gd) electrocatalyst to enhance electrochemical oxidation in an alkaline electrolyte. The synergistic interaction between Ln and Fe in the magnetic material significantly increased the electrochemically active surface area (EASA), facilitated the formation of oxygen, hydrogen peroxide, and peroxo intermediate species, and reduced the activation energy of the rate-limiting step for La/Fe 3 O 4 @MIL-53(Fe) (8.77 kJ∙mol −1 ) compared with Fe 3 O 4 @MIL-53(Fe) (21.31 kJ∙mol −1 ). This study presents a viable strategy for the design of efficient nonprecious metal OER catalysts for water electrolysis.