Computational Screening of Single-Atom Anchored All-Boron Cage (B₂₈) for Hydrogen Evolution Reaction

The electrocatalytic hydrogen evolution reaction (HER) is a crucial step in the production of hydrogen through the electrolysis of H2O. Platinum-based materials are regarded as the most effective catalysts for HER due to their low overpotential and high stability. However, the scarcity and high cost of platinum limit its application on a large scale. In this study, we employed first-principles methods to investigate the HER performance of a series of single-atom catalysts based on the B28 cluster. This cage-like B28 cluster shows instability for only five out of 40 metal atom candidates, which can be attributed to the presence of hexagonal and octagonal holes that allow for effective anchoring of single atoms. We utilized the integrated crystal orbital Hamiltonian population (ICOHP) as a vital descriptor to assess the strength of the interaction between the metal atoms and the B28 cluster, demonstrating a linear correlation with binding energy. By calculating changes in Gibbs free energy (ΔGH*) for hydrogen absorption, we identified four species (Ge@B28, Cu@B28, Ni@B28, and Pt@B28) that exhibit superior HER catalytic activity with |ΔGH*| around 0.2 eV. Moreover, our results indicate that these four species are more likely to produce H2 through the Tafel reaction. This study provides evidence that boron clusters have the potential to serve as single-atom supports and as catalysts for HER. These findings establish a theoretical foundation for the experimental design of novel nanocatalysts.