Graphenylene-Based Single Atom Catalyst for Green Hydrogen Production from Water Electrolysis

The transition to clean and renewable energy sources is crucial for mitigating climate change. However, providing clean and renewable energy is challenging due to the intermittent nature of some sources like solar and wind, demanding flexible and scalable technologies for clean energy production and storage. Green hydrogen, produced by water electrolysis, is a promising alternative due to its high energetic density, neutral carbon footprint, and versatility in energy harvesting applications¹. Nonetheless, its production in the electrochemical Hydrogen Evolution Reactions (HER) is hindered by the need for efficient, abundant, and low-cost catalysts as an alternative to the scarce and expensive noble metal-based materials. Carbon-based two-dimensional nanostructures offer high surface area, chemical stability, and the possibility of tunning electronic properties, offering a pathway to tailor catalytic activity². Specifically, using single metal atoms as active sites (Single Atom Catalysts, SACs) can effectively promote catalysis while minimizing metal usage and maximizing atomic efficiency. In this work, we apply first-principles calculations based on Density Functional Theory (DFT) to investigate the catalytic activity of Graphenylene (GPY) within the Computational Hydrogen Electrode (CHE) model³ framework. Our results show that Sc, Ti, Mo, Zr, Pt, Ni, and Co GPY-based SAC are promising for HER catalysis achieving |ΔG_H| &lt; 0.1 eV, while pristine GPY exhibits weak hydrogen binding (ΔG_H = +0.83 eV). The enhancement in the catalytic activity is attributed to the promotion of charge transfer and the formation of bonding states between the metal and the hydrogen intermediate modulating the free energy of adsorption. This work contributes to the development of new carbon-based catalysts providing fundamental insights on the catalytic properties from the atomistic perspective.<br/><b>Acknowledgments</b><br/>The authors thank PRH.49 (PRH-ANP UFABC) and CNPq (grant 308428/2022-6) for funding and the UFABC Multiuser Computational Center (CCM-UFABC) for the computational resources provided.<br/><b>References</b><br/>[1] Safari, F., & Dincer, I. (2020). Energy Conversion and Management, 205, 112182.<br/>[2] Lv, Y., Chen, G., Ma, R., Yong Lee, J., & Kang, B. (2024). Fuel, 357, 130017.<br/>[3] Nørskov, J. K., Rossmeisl, J., Logadottir, A., Lindqvist, L., Kitchin, J. R., Bligaard, T., & Jónsson, H. (2004). The Journal of Physical Chemistry B, 108(46), 17886–17892.