Unlocking the Future of Green Hydrogen: Innovations in Single Atom Catalysts
Tüysüz group publishes two exciting papers in high-level journals
How can the energy needs of humankind be met sustainably in the future? Scientists at the Max Planck Institut für Kohlenforschung are getting to the bottom of this question - using very specific catalysts, among other things.
The growing need for sustainable energy solutions has placed hydrogen production via water electrolysis into the spotlight of clean energy research. At the Max-Planck-Institut für Kohlenforschung (MPI-KOFO), researchers in the group of PD. Dr. Harun Tüysüz are working on developing advanced single-atom catalysts (SACs) to improve the efficiency and stability of the oxygen evolution reaction (OER) of water electrolysis. Two landmark studies, recently published in the Journal of the American Chemical Society (JACS) and Advanced Materials in 2024, highlight innovations in SACs, which offer promising steps toward scalable green hydrogen production. SACs are emerging as next-generation catalysts due to their well-defined atomic sites, high atom efficiency, and tunable interactions with support materials, making them ideal for energy conversion applications.
The investigations and collaborations in the framework of FUNCAT, supported by the Max Planck Society, between Harun Tüysüz at MPI-KOFO and Serena DeBeer's team at the Max Planck Institute for Chemical Energy Conversion, reveal new ways to improve the stability of iridium (Ir) single atoms on oxide supports under harsh OER conditions, which remains a major challenge for large-scale hydrogen production.
The first study led by Alexander von Humboldt Fellowship holder Dr. Ashwani Kumar, featured in JACS, presents a novel approach for enhancing Ir-SACs stability for alkaline OER by regulating the local coordination sphere of Ir single atoms on nickel oxide. By adjusting the second coordination shell, the team demonstrated a remarkable improvement in both activity and long-term stability, surpassing the performance of commercial IrO₂. This stability improvement is attributed to increased Ir-Ni second-shell coordination, which shields the single atoms from leaching during the OER process, thereby ensuring long-lasting performance with minimal degradation. The work demonstrates that precise control of the atomic environment around Ir atoms can mitigate metal leaching and provide sustained catalytic performance, crucial for large-scale hydrogen production.
The second groundbreaking research article, published in Advanced Materials, shifted attention to acidic OER, where stability is even more challenging. The team explored the use of Ir single atoms on cobalt oxide supports and investigated how the spatial arrangement of Ir atoms could be controlled through modifications to the cobalt oxide matrix. Specifically, the substitution of manganese into the cobalt oxide framework induced the migration of Ir single atoms, forming short-range Ir ensembles with a unique bond length of 2.6 Å. These Ir single-atom ensembles followed an unconventional oxide-path mechanism that promoted direct O-O coupling, bypassing the traditional adsorbate evolution mechanism. This shift in reaction mechanism not only improved the catalytic efficiency but also enhanced the stability of the catalysts in acidic media where conventional SACs often fail due to rapid metal dissolution.
As the global energy landscape shifts towards renewable solutions, SACs are poised to revolutionize industries ranging from energy conversion to chemical manufacturing. The work conducted at MPI-KOFO sets the stage for further exploration of SACs in diverse energy applications, particularly in the large-scale deployment of green hydrogen technologies.
