Abstract 

Carbon fiber-based electrocatalysts offer significant advantages over conventional powder catalysts, including enhanced active site exposure, superior conductivity, faster reaction rates, lower costs, and improved stability under harsh conditions. In this study, we introduce a rapid and scalable method for spinning carbon-supported metal catalysts into their fibrous forms to achieve uniform catalyst structures that enable roll-to-roll manufacturing. We demonstrate uniform ruthenium (Ru) nanoparticle-loaded carbon fibers by spinning polyacrylonitrile (PAN)-Ru phenanthroline complexes and annealing at 1200 °C for the optimum Ru particle size distribution. We found that the interaction of the Ru complex with the nitrile (−C≡N) group of PAN enabled rheological control and ensured monodisperse Ru confinement. Our investigation of the mechanism details the microstructural evolution during carbonization and oxygen plasma treatment, showing exceptional enhancement in the performance of Ru-embedded carbon fabric electrocatalysts. Ultimately, our rheology-driven spinning protocol bridges the gap between laboratory-scale synthesis and industrial manufacturing of fabric electrocatalysts, providing a versatile platform for nanoconfinement that offers critical insights into the structural evolution of metal–polymer nanocomposites for next-generation energy applications.

A research team affiliated with UNIST has introduced a scalable process to produce long-lasting, fiber-shaped electrodes for water electrolysis, paving the way for large-scale hydrogen production.

Professor Han Gi Chae of the Department of Materials Science and Engineering and Professor Jong-Beom Baek of the School of Energy and Chemical Engineering collaborated with Professor Cafer T. Yavuz at King Abdullah University of Science and Technology (KAUST).

Traditional electrodes rely on coating catalysts onto conductive substrates, often using binders that block active surfaces. In contrast, these new fibers act as both support and conductor, allowing water and electrolytes to flow freely and hydrogen to escape efficiently.

Central to this method is the embedding of ruthenium particles within the polymer fibers, resulting in improved catalyst dispersion and durability. By mixing a viscous polymer-Ru precursor and extruding it through a nozzle, the team produced continuous fibers. When heat-treated at 1200°C, these fibers develop a uniform distribution of catalytic nanoparticles inside and on the surface, preventing clumping and ensuring consistent activity.

Achieving this required precise control over the interaction between the Ru precursor and the polymer. The researchers optimized the conditions to maintain even dispersion during fiber formation. They further enhanced the surface exposure of catalytic sites through oxygen plasma treatment, significantly improving performance and stability.

Testing showed that these fibers could operate continuously for more than 170 hours at a high current density of 500 mA/cm² without degradation. Their catalytic activity surpassed that of conventional platinum electrodes, highlighting their potential for practical applications.

The study was primarily led by Dr. Ga-Hyeun Lee from UNIST and Professor Seok-Jin Kim from KAUST, who served as the first authors, with researcher Inkyung Baek contributing as a co-author. This research offers new insights into the microstructural evolution of metal-polymer nanocomposites and demonstrates a scalable approach to fabricating fiber electrodes for efficient hydrogen production.

Professor Chae noted, “Embedding metal catalysts uniformly within carbon fibers enhances electrode stability. This technique could extend beyond water electrolysis to other catalytic systems where durability and uniform reactivity are crucial.”

The research was published in  ACS Nano (Impact Factor: 16.1, Cite Score: 24.2)Impact Factor: 16.1, Cite Score: 24.2) on May 7, and supported by the Ministry of Science and ICT (MSIT), the Ministry of Education (MOE), and the National Research Foundation of Korea (NRF).

Journal Reference

Ga-Hyeun Lee, Seok-Jin Kim, Jung-Eun Lee  , et al.,  “Rheological Pathways to a Scalable Ruthenium Nuclei-Anchored Carbon Fiber Catalyst,”   ACS Nano,  (2026).