Theoretical investigations into the hydrogen evolution reaction of the carbon schwarzites: From electronics to structure-catalytic activity relationship

Since Earth-abundant materials have received considerable attention for energy applications, interest in developing new carbon-based structures actively continues. One such material, the 3D carbon-based schwarzite structure, has the unusual shape of Triply-Periodic Minimal Surfaces (TPMS) and shows a stable curvature formed of carbon rings with more than six atoms. However, the possibility of application as a catalytic material has not been discussed, even though their geometric and electronic features can improve reactivity with diverse catalytic adsorbents. Herein, we systematically investigated the hydrogen evolution reaction (HER) activity of diverse schwarzites based on thermodynamic, electronic, and geometric viewpoints. Our results reveal that the h8326896 structure has superior HER catalytic activity with binding free energy of hydrogen (ΔG_H^∗) as −0.02 eV, closer to that of the ideal catalyst (0 eV). Based on this thermodynamic result, we explored the reason for the remarkable activity and found that efficient hydrogen binding clearly originates from the favourable p-orbital tendency with a metallic nature and positively curved geometry. Therefore, we believe that this work will play an important role in uncovering and extending the utility of carbon-based schwarzites as catalytic materials.