Structure growth, stability and adsorption properties of (AgZn3)n clusters

• Published in: Molecular physics 2024-12, Vol.122 (24)
• Main Authors: Li, Huijuan, Zhang, Enli, Yuan, Ming, Liu, Qiman, Liu, Changqing
• Format: Article
• Language: English
• Subjects: adsorptions; AgZn clusters; Atomic structure; Clusters; Configurations; Density functional theory; Doppler effect; electronic structures; Genetic algorithms; geometry features; Hydrogen production; Molecular orbitals; Orbital stability; Red shift; Silver; Synthesis gas; Zinc
• ISSN: 0026-8976; 1362-3028
• DOI: 10.1080/00268976.2024.2341961

Recently, an effective syngas catalyst composed of AgZn 3 clusters is reported, in which the CO and H 2 generation may occur at the Zn sites and the hollow sites between Ag and Zn. Hence, the atomic model of the AgZn 3 is worth established to further investigate the catalytic mechanism. Here, we take advantage of the genetic algorithm with the density functional theory to unbiasedly search configurations of (AgZn 3 ) n (n = 1-6) clusters. It is found that (AgZn 3 ) n clusters evolve from hollow cages to close-packed structures, with Zn atoms gradually occupying the core positions. The E b and Δ 2 E analyses show that the (AgZn3) 3 has a higher stability than that of its neighbors. The AIMD simulations demonstrate that the (AgZn 3 ) 3 shows a favorable stability at 700 K. The molecular orbitals reveal that 21 valence electrons of the (AgZn 3 ) 3 fill superatomic orbits resulting in an electronic configuration of 1S 2 1P 6 1D 10 2S 2 1F 1 . The adsorptions of CO on the bridge sites of (AgZn 3 ) 3 are much higher in energy than the top adsorptions, but the red shift of the stretching frequency of C-O is more obvious in the former. Our results are verified that the Zn sites and bridge sites between Ag and Zn are active sites for CO.