Highlighting the Potential of Synergistic Cu-Pt Single-Atom Alloy Sub-nanoclusters for Enhanced H2 Adsorption: A DFT Investigation.

Abstract

Single-atom alloy sub-nanoclusters offer promising potential for understanding intricate interfacial phenomena at the atomic level, enabling the rational design of efficient catalysts and nanomaterials for H₂ energy storage, purification, and conversion. Herein, we employed density functional theory calculations improved by van der Waals corrections to investigate H₂ adsorption on pure copper (Cu _n ) and copper-platinum (Cu _n-1Pt) sub-nanoclusters. We characterized Cu _n sub-nanoclusters ranging from n = 2 to n = 14, identifying the most stable sizes (4, 6, 8, 10, and 12) through a set of stability analysis. Subsequently, we substituted a single Cu atom with Pt to form single-atom alloy Cu _n-1Pt sub-nanoclusters, which showed enhanced stabilization and reactivity compared to pure Cu sub-nanoclusters. While Cu-only sub-nanoclusters exhibited weak side-on interactions with H₂, resulting in minimal charge transfer and negligible structural changes, CuPt-based sub-nanoclusters showed strong interactions characterized by molecular dissociation (H-H bond breaking) and significant charge transfer from the sub-nanoclusters to the H atoms. These findings highlight the synergistic effects of the Cu-Pt combination and provide valuable insights into the fundamental processes of H₂ adsorption on metal sub-nanoclusters, with significant implications for catalytic applications and materials design in hydrogen-related technologies.