A Computational Map of the Probe Co Molecule Adsorption and Dissociation on Transition Metal Low Miller Indices Surfaces

Abstract

The adsorption and dissociation of carbon monoxide (CO) have been studied on 81 Transition Metal (TM) surfaces, with TMs having body centred cubic (bcc), face centred cubic (fcc), or hexagonal close-packed (hcp) crystalline structures. For each surface, CO, C, and O adsorptions, and C+O co-adsorptions were studied by density functional theory calculations on suited slab models, using Perdew-Burke-Ernzerhof functional with Grimme’s D3 correction for dispersive forces. CO dissociation activation and reaction energies, ΔE, were determined. The values, including zero point energy, were used to capture chemical trends along groups, d-series, and crystallographic phases concerning CO adsorption and dissociation, while simulated infrared (IR) spectroscopies and thermodynamic phase diagrams are provided. Late fcc TMs are found to adsorb CO weakly, perpendicularly, and are IR-visible, opposite to early bcc TMs, while hcp cases are distributed along these two extremes. The d-band centre, εd, is found to be the best descriptor for CO adsorptions and C+O co-adsorptions, ΔE, and activation energies. The implications of the found trends and descriptors are discussed on processes requiring CO dissociation, such as Fischer-Tropsch.

Keywords: DFT, transition metal surfaces, CO, adsorption, Dissociation, descriptors