ANN and DFT investigation of 55-atom icosahedral Ag-Pt nanoalloys: Understanding structure, dynamics, and [formula omitted] activation

Abstract

An artificial neural network (ANN)–based interatomic potential has been constructed to examine the structural properties of Ag55−nPtn nanoalloys, where n= 0–14. We conducted molecular dynamics simulations for global-optimizations of these nanoalloys using ANN-based interatomic potential. The relative stability of the Ag-Pt nanoalloys has been studied using stability indicators such as cohesive energy, excess energy and interaction energy. Additionally, we analyse the adsorption of O2 and CO molecules on Ag55−nPtn nanoalloys using the first-principles density functional theory based (DFT) method. The presence of Pt doping has been found to increase the adsorption strength of O2 and CO on the Ag55−nPtn nanoalloys compared to the pure Ag55 nanocluster. Our investigation suggests that the presence of Pt atoms in the core of the nanoalloy has a relatively minor effect on the adsorption of O2 and CO in comparison to Pt atoms present on the surface. The adsorption of O2 and CO on Ag41Pt14 nanoalloy, in which one of the Pt atoms is present at the surface of the nanoalloy, shows strongest adsorption among all the compositions of Ag55−nPtn nanoalloys.