Mechanistic insights into the hydrogen evolution reaction catalyzed by ConMoP (n = 1–5) clusters

To investigate the catalytic activity of Co_nMoP (n = 1–5) clusters with water molecules for hydrogen evolution reaction (HER), a systematic analysis was performed using density functional theory (DFT). Using the B3LYP functional and def2-TZVP basis set, the structures of the clusters with different spin multiplicities were optimized and theoretically calculated using the Gaussian16 software package. To evaluate the catalytic performance of these clusters, we focused on analyzing their HOMO-LUMO energy gaps, Gibbs free energy changes (ΔG), and electron density distributions. The results show that the ΔG_H* value of configuration 1-a is closest to 0, indicating its excellent catalytic performance for HER; additionally, the Co atom was identified as the primary active site. Configuration (5-b)-H_ads exhibited the smallest energy gap, demonstrating the strongest catalytic activity. Configurations 1-a, 2-a, and 5-b were identified as the most promising catalysts in this series of clusters. This study reveals the behavior of transition metal clusters in catalytic reactions and provides a reference for future experimental and theoretical research.