Advancements of metal organic frameworks for electrocatalytic applications: Water splitting electrolysis and proton exchange membrane fuel cell

The transition toward a sustainable hydrogen economy requires the development of efficient, durable, and cost-effective electrocatalysts for both hydrogen production and utilization. Metal-organic frameworks (MOFs) have emerged as promising materials owing to their exceptionally high surface area, tunable porosity, structural versatility, and abundant accessible active sites. However, their practical application is limited by poor electrical conductivity and inadequate electrochemical stability. To overcome these limitations, significant research has focused on bimetallic MOFs and MOF-derived materials, which exploit synergistic interactions between multiple metal centres to enhance charge transport, catalytic activity, structural robustness, and corrosion resistance. This review provides a comprehensive overview of MOFs, covering their classification, synthesis strategies, structural properties, and the preparation of bimetallic MOFs through direct synthesis, post-synthetic modification, and template-assisted approaches. Furthermore, the MOF-derivatives are discussed, highlighting their superior conductivity and catalytic performance. The electrocatalytic applications of these materials in the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen oxidation reaction (HOR) are critically evaluated by correlating structural characteristics with electrochemical performance. Finally, the remaining challenges, including scalable synthesis, structural stability, reproducibility, and long-term durability, are discussed together with future opportunities involving rational catalyst design, defect engineering, advanced characterization, and machine learning-assisted materials discovery. This review provides valuable insights into the design of next-generation MOF-based electrocatalysts for efficient water electrolysis and proton exchange membrane fuel cells, contributing to the advancement of sustainable hydrogen energy technologies.