Ab Initio Molecular Dynamics Study of Dissociative Chemisorption and Scattering of CO₂ on Ni(100): Reactivity, Energy Transfer, Steering Dynamics, and Lattice Effects

Abstract

The dissociative chemisorption of polyatomic molecules on metal surfaces has attracted much interest in recent years due to their industrial and fundamental importance. Comparing with extensively studied systems such as methane and water, however, dissociative chemisorption of CO2, which is important for CO2 activation, has so far received scant attention. We recently reported vibrational enhancement of the dissociative chemisorption of CO2 on a rigid Ni(100) surface using a nine-dimensional potential energy surface (PES) based on a large number of density functional theory calculations. However, that PES is incapable of describing the lattice motion and energy transfer between this heavy molecule and the surface. To overcome these limitations, we present here ab initio molecular dynamics results for CO2 scattering and dissociation. In addition to formation of adsorbed O and CO, CO2 is found to have a large trapping probability in a chemisorption well, along with a substantial amount of energy loss to surface phonons. The lattice and dynamical steering effects are found to be quite different from what have been observed for direct dissociative chemisorption of methane and water.

Energy dissipation at metal surfaces

“…This additional effect of vibrational surface motion can play an important role in the adsorption dynamics, as demonstrated prominently for (direct) CH 4 dissociation at several metal surfaces [76]. Here (as also in other reported instances [77,78]), DFT calculations specifically showed significant lowering of the activation barrier as a metal atom is puckered out of the surface at the transition state [79,80]. Effectively accounting for both of the aforementioned effects through two (independent) DFT-derived adsorbatesurface coupling parameters [81], the quantum dynamics simulations of Jackson and coworkers thus arrived at a semi-quantitative agreement to experimental sticking curves (also reproducing the observed mode specificity and bond selectivity) that could not otherwise be achieved on the SO level alone [82].…”

“…Indeed, for the aforementioned CH 4 dissociation (where both effects are known to be important [76]) Kroes and coworkers predicted satisfying, semi-quantitative agreement to experimental reaction probabilities [84]. In the meantime, similar results have also been reached for H 2 [37,85,86], N 2 [87,88], O 2 [89], and CO 2 [78] adsorbates, overall showing AIMD simulations to provide a reasonable account of surface temperature effects. With reaction probabilities as the target observable, the effective advantage of the detailed AIMD account of adsorbate-surface energy transfer-over corresponding, numerically more attractive SO/GLO modelsultimately depends on the importance of thermal fluctuations (assuming of course the validity of the single-phonon approximation).…”

Origin of Thermal and Hyperthermal CO2 from CO Oxidation on Pt Surfaces: The Role of Post‐Transition‐State Dynamics, Active Sites, and Chemisorbed CO2

“…This work shows that investigations of steps and other defects could be potentially important in finding optimal conditions for the chemical activation of CO 2 . Also, the apparent excitation of the asymmetric stretching vibration in the CO 2 production as seen in our dynamics simulations suggests that this mode may be helpful in dissociative CO 2 adsorption, as already proposed …”

Desorption dynamics of CO2 from formate decomposition on Cu(111)

“…This is in contrast to the case of CO oxidation, where CO 2 was found to spend a significant residence time in the chemisorption well before it desorbs. 30 Moreover, one of the two C-O bond lengths of CO 2 is significantly elongated at the TS of CO oxidation, and carbon and oxygen are strongly bonded to the surface. 31 In summary, we have investigated the minimum energy path of CO 2 hydrogenation into formate and the dynamics of formate decomposition into gas phase CO 2 and adsorbed hydrogen using density functional theory calculations.…”