Eley Rideal recombination of hydrogen atoms on Cu(111): Quantitative role of electronic excitation in cross sections and product distributions

Abstract

Eley-Rideal (ER) reaction between a projectile and an adsorbate at a gas-surface interface represents many interesting dynamic features. Electron-hole pairs (EHPs) could play an important role in this process, given the interaction between the accelerated incident atom/molecule and the surface electrons. Here, we examine the EHP effects in a benchmark ER reaction of an impinging H/D atom and pre-covered D/H atoms on Cu(111) by ab initio molecular dynamics simulations. It is found that energy dissipation to EHPs lowers the reaction cross sections by ∼1/3, mainly due to the suppression of the hot atom mechanism, but has a minor effect on rotational distributions, leading to quantitative agreement with experimental data. More interestingly, electronic excitation is responsible for the isotopic effect in translational energy distributions, but probably not for that in angular distributions. Our results highlight the specific role of electronic excitation in detailed dynamic quantities in the ER process.

Computational approaches to dissociative chemisorption on metals: towards chemical accuracy

“…Additionally, the optPBE-vdW 331 SRP-DF 150 was used successfully to model the abstraction of D by H or H by D from Cu (111) resulting in HD. 583 Specifically, the DFMDEF calculations using this SRP-DF showed quantitative agreement with experiments 666 concerning the abstraction cross section, the final rotational state and angular distributions of HD, and the final average E t of HD. The calculations also showed that modeling ehp excitation was necessary to reach a high level of agreement, which could be explained in terms of energy loss by the incident atom being more important for the hot atom reaction of the lighter (H) incident atom.…”

“…74,582 DFMDEF calculations also addressed energy dissipation upon DC of H 2 on Pd(100). 74,114,582 Another topic addressed with DFMDEF is Eley-Rideal reactions, of H-atoms on Cu(111), 583 of D-atoms with CD 3 pre-adsorbed to Cu(111), 584 and of H with Cl preadsorbed to Au (111). 585 Finally, DFMDED calculations investigated scattering of N-atoms from Ag(111), 74,541,582 and dynamic displacement of CO pre-adsorbed to Cu (111) by incident H-atoms.…”

“…The calculations also showed that modeling ehp excitation was necessary to reach a high level of agreement, which could be explained in terms of energy loss by the incident atom being more important for the hot atom reaction of the lighter (H) incident atom. 583 Only the final vibrational state distribution was not yet well described by the DFMDEF, which the authors attributed to shortcomings of the QCT method. 583 It remains to consider the implications of the theory-experiment comparison for H 2 + Cu (111) for the accuracy of GGA-DFT for DC on metals in general.…”

“…583 Only the final vibrational state distribution was not yet well described by the DFMDEF, which the authors attributed to shortcomings of the QCT method. 583 It remains to consider the implications of the theory-experiment comparison for H 2 + Cu (111) for the accuracy of GGA-DFT for DC on metals in general. Like initial-state selected reaction probability curves (see Section 4.6), sticking probabilities can be fitted to S-shaped curves characterized by a width (or, inversely, the slope), and an effective barrier height (E 0 ) or, alternatively, a reaction threshold, where the latter should correspond closely with the minimum barrier height.…”

Neural Network Representations for Studying Gas‐Surface Reaction Dynamics: Beyond the Born‐Oppenheimer Static Surface Approximation†

“…It should be noted that the explicit construction of a PES can be avoided by running direct dynamics, where the forces acting on nuclei are computed on‐the‐fly during (quasi‐)classical trajectories. While this so‐called ab initio molecular dynamics (AIMD) method has been frequently applied in studying gas‐surface reactions, [ 36‐45 ] it remains very expensive for rare and/or long‐time events and is not our topic here. Indeed, recent neural network based methods have substantially accelerated the atomistic simulation of surface reaction dynamics, which can be now routinely studied beyond the Born‐Oppenheimer static surface approximation.…”