Hydrogen adsorption and dissociation on AunY (n = 1–12) nanoclusters: a DFT investigation

Abstract

The interaction between nanomaterial systems and hydrogen has recently emerged as a compelling study model, offering valuable insights for designing materials with applications in nanotechnology, catalysis, and energy storage. Among these, transition metal-doped gold clusters exhibits intriguing stability and electronic properties, making them promising candidates for hydrogen related processes. In this study, we employ density functional theory (DFT) to investigate the interaction between H₂ molecules and small-sized gold clusters doped with yttrium. Our finding reveals that most of the bare cluster structures remain intact during the H₂ adsorption, regardless of whether the process occurs molecularly or dissociatively. A comprehensive analysis indicates that the preferred adsorption configuration is governed by multiple factors, including adsorption site (surface vs. encapsulated), relative electronegativity, and the atomic coordination number. The calculations demonstrate that dissociative adsorption of H₂ on Au₆Y and Au₁₁Y clusters is both thermodynamically and kinetically favorable. However, for Au_nY (n = 1, 4–5, 8, 10) dissociative adsorption is hindered by a significant energy barrier before reaching the final state, while for species with n = 2, 3, 7, and 9 molecular adsorption is more favorable due to intrinsic energy preferences. This study provides fundamental insights into the adsorption sites and detailed analysis of adsorption kinetics on Au_nY clusters, laying the groundwork for further theoretical an ed experimental investigations into the hydrogenation process in nanostructured materials.