Ab initio screening of Pt-based transition-metal nanoalloys using descriptors derived from the adsorption and activation of CO2

Abstract

In this study, we report an ab initio screening, based on density functional theory calculations, of Pt-based transition-metal nanoalloys using physicochemical descriptors derived from the adsorption and activation of CO₂ on 55-atom nanoclusters, namely, Pt_nTM_55−n, with n = 0, 13, 42, 55, TM = Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Os, Ir, Au. From the adsorption on the unary and binary nanoclusters, at the chemisorption regime (bent CO₂), we identified a linear correlation between the interaction energy and charge transfer from the nanoclusters towards CO₂ and the bent CO₂ angle; moreover, the interaction energy is enhanced for larger values of the molecular charge and angle. The alloying of Cu₅₅, Ag₅₅, and Au₅₅ with Pt provides a path to change the CO₂ adsorption from physisorption (linear, non-activated) to chemisorption (enhanced interaction energies, bent, activated), while the strong interaction energy of CO₂ with Os₅₅, Ru₅₅, and Fe₅₅ can be decreased by alloying with Pt using different structural configurations, i.e., the trends are similar for core–shell and segregated structures. Thus, based on our results and analyses, we can select different combinations of Pt_nTM_55−n nanoalloys to yield the desired interaction strength and magnitude of the charge transfer towards the activated anionic CO₂, which can help in the design of nanocatalysts for CO₂ activation or different chemical reactions in which charge transfer plays a crucial role.