Evidence for Electron–Hole Pair Excitation in the Associative Desorption of H<sub>2</sub> and D<sub>2</sub> from Au(111)

Shuai, Quan; Kaufmann, Sven; Auerbach, Daniel J.; Schwarzer, Dirk; Wodtke, Alec M.

doi:10.1021/acs.jpclett.7b00265

Cited by 25 publications

(119 citation statements)

References 34 publications

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“…Using this loss factor, the theory predicts that H-adsorption-induced chemicurrent (=10 −2 × 3.5 × 10 −5 e/H) is much smaller than that seen in experiment (5 × 10 −5 e/H). This analysis is consistent with previous work suggesting that only the H-H recombination reaction on Au produces hot electrons (24) and chemicurrent (13). We also note that the H-adsorption-induced chemicurrents seen by Schottky diode experiments on Ag surfaces (7,11) were performed at a surface temperature (100-135 K) far lower than the H 2 recombinative desorption temperature (∼170 K) (25).…”

Section: Significancesupporting

confidence: 92%

“…In photocatalysis, hot electrons may interact with surface adsorbates to make and break bonds (28). The rate of a reaction on a metal surface is governed by the rate of passage through the transition state of the reaction, which may be influenced by energy dissipation to electronic degrees of freedom (24,29). If the coupling is too strong, transitionstate theory may even break down.…”

Section: Significancementioning

confidence: 99%

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Unified description of H-atom–induced chemicurrents and inelastic scattering

Kandratsenka

Jiang

Dorenkamp

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

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The Born-Oppenheimer approximation (BOA) provides the foundation for virtually all computational studies of chemical binding and reactivity, and it is the justification for the widely used "balls and springs" picture of molecules. The BOA assumes that nuclei effectively stand still on the timescale of electronic motion, due to their large masses relative to electrons. This implies electrons never change their energy quantum state. When molecules react, atoms must move, meaning that electrons may become excited in violation of the BOA. Such electronic excitation is clearly seen for: (i) Schottky diodes where H adsorption at Ag surfaces produces electrical "chemicurrent;" (ii) Au-based metal-insulator-metal (MIM) devices, where chemicurrents arise from H-H surface recombination; and (iii) Inelastic energy transfer, where H collisions with Au surfaces show H-atom translation excites the metal's electrons. As part of this work, we report isotopically selective hydrogen/deuterium (H/D) translational inelasticity measurements in collisions with Ag and Au. Together, these experiments provide an opportunity to test new theories that simultaneously describe both nuclear and electronic motion, a standing challenge to the field. Here, we show results of a recently developed first-principles theory that quantitatively explains both inelastic scattering experiments that probe nuclear motion and chemicurrent experiments that probe electronic excitation. The theory explains the magnitude of chemicurrents on Ag Schottky diodes and resolves an apparent paradox--chemicurrents exhibit a much larger isotope effect than does H/D inelastic scattering. It also explains why, unlike Ag-based Schottky diodes, Au-based MIM devices are insensitive to H adsorption.M ost theoretical studies of atoms and molecules interacting with metal surfaces are based on the Born-Oppenheimer approximation (BOA) (1). However, a growing number of examples have been found where electronic and nuclear degrees of freedom are strongly coupled in violation of the BOA (2-6). H-atom interactions at metals offer a remarkable opportunity to test non-BOA theories against experiment, since H-adsorptioninduced chemicurrent experiments (7-14) offer a direct measure of electronic excitation and H-atom inelastic scattering experiments (15) directly probe nuclear motion. In chemicurrent experiments, exothermic H interactions like adsorption and recombination produce hot electrons that pass over a potential barrier to be collected. Hence, the magnitude of the chemicurrent is dependent on both the reaction-induced production of hot electrons and the likelihood of transmission over the barrier. To reduce uncertainties associated with barrier transmission, the ratio of hydrogen-and deuterium-induced chemicurrent is often measured--H-induced chemicurrents are typically two to five times larger than those from D atoms (7,(11)(12)(13). H-atom surface scattering experiments yield H-atom translational energy loss distributions. The importance of H-atom translation to electronic exc...

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Section: Significancesupporting

confidence: 92%

Section: Significancementioning

confidence: 99%

Unified description of H-atom–induced chemicurrents and inelastic scattering

Kandratsenka

Jiang

Dorenkamp

et al. 2018

Proc. Natl. Acad. Sci. U.S.A.

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“…[28], with recent molecular scattering experiments adding new evidence for its experimental relevance. [29] Unfortunately, the computational cost of TDPT models hitherto did not allow their routine application in full-dimensional molecular dynamics simulations (MD), leaving questions relating to EHP-induced effects on dynamical steering or mode-specific energy redistribution unanswered.…”

mentioning

confidence: 99%

“…The strong frictional mode specificity along the intramolecular stretch is visible in a more effective loss of rovibrational energy than translational energy, serving as a potential experimental signature of mode-specific nonadiabatic effects. [29] Electronic friction originates from the coupling of electronic excitations with adsorbate nuclear motion. This effect can be captured within mixed quantum-classical theories.…”

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confidence: 99%

Mode Specific Electronic Friction in Dissociative Chemisorption on Metal Surfaces: H2 on Ag(111)

et al. 2017

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(2017) Mode specific electronic friction in dissociative chemisorption on metal surfaces : H2 on Ag(111). Physical Review Letters, 118. 256001. Permanent WRAP URL:http://wrap.warwick.ac.uk/96012 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for-profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher statement: © 2017 American Physical Society A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP URL' above for details on accessing the published version and note that access may require a subscription. Electronic friction and the ensuing nonadiabatic energy loss play an important role in chemical reaction dynamics at metal surfaces. Using molecular dynamics with electronic friction evaluated on-the-fly from Density Functional Theory, we find strong mode dependence and a dominance of nonadiabatic energy loss along the bond stretch coordinate for scattering and dissociative chemisorption of H2 on the Ag(111) surface. Exemplary trajectories with varying initial conditions indicate that this mode-specificity translates into modulated energy loss during a dissociative chemisorption event. Despite minor nonadiabatic energy loss of about 5%, the directionality of friction forces induces dynamical steering that affects individual reaction outcomes, specifically for low-incidence energies and vibrationally excited molecules. Mode-specific friction induces enhanced loss of rovibrational rather than translational energy and will be most visible in its effect on final energy distributions in molecular scattering experiments.

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“…Conventional MD is based on two assumptions: (a) the Born–Oppenheimer (adiabatic) approximation which separates the electronic and nuclei motion, reducing the nuclei motion on a single adiabatic potential energy surface (PES) and (b) the classical treatment of the nuclei. Processes such as electron transfer, charge transport, electronic friction at metal surfaces and nonradiative decay after photoexcitation often involve multiple PESs, with nonadiabatic (NA) transitions among them. In addition, for systems containing small mass elements, for example, hydrogen, zero‐point motion and tunneling effects may not be ignored and as a result require a quantum mechanical description of the nuclei .…”

Section: Introductionmentioning

confidence: 99%

Ab initio nonadiabatic molecular dynamics investigations on the excited carriers in condensed matter systems

Zheng

Chu

Zhao

et al. 2019

WIREs Comput Mol Sci

272

258

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The ultrafast dynamics of photoexcited charge carriers in condensed matter systems play an important role in optoelectronics and solar energy conversion. Yet it is challenging to understand such multidimensional dynamics at the atomic scale. Combining the real‐time time‐dependent density functional theory with fewest‐switches surface hopping scheme, we develop time‐dependent ab initio nonadiabatic molecular dynamics (NAMD) code Hefei‐NAMD to simulate the excited carrier dynamics in condensed matter systems. Using this method, we have investigated the interfacial charge transfer dynamics, the electron–hole recombination dynamics, and the excited spin‐polarized hole dynamics in different condensed matter systems. The time‐dependent dynamics of excited carriers are studied in energy, real and momentum spaces. In addition, the coupling of the excited carriers with phonons, defects and molecular adsorptions are investigated. The state‐of‐art NAMD studies provide unique insights to understand the ultrafast dynamics of the excited carriers in different condensed matter systems at the atomic scale. This article is categorized under: Structure and Mechanism > Computational Materials Science Molecular and Statistical Mechanics > Molecular Dynamics and Monte‐Carlo Methods Electronic Structure Theory > Ab Initio Electronic Structure Methods Software > Simulation Methods

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Evidence for Electron–Hole Pair Excitation in the Associative Desorption of H₂ and D₂ from Au(111)

Cited by 25 publications

References 34 publications

Unified description of H-atom–induced chemicurrents and inelastic scattering

Unified description of H-atom–induced chemicurrents and inelastic scattering

Mode Specific Electronic Friction in Dissociative Chemisorption on Metal Surfaces: H2 on Ag(111)

Ab initio nonadiabatic molecular dynamics investigations on the excited carriers in condensed matter systems

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Evidence for Electron–Hole Pair Excitation in the Associative Desorption of H2 and D2 from Au(111)

Cited by 25 publications

References 34 publications

Unified description of H-atom–induced chemicurrents and inelastic scattering

Unified description of H-atom–induced chemicurrents and inelastic scattering

Mode Specific Electronic Friction in Dissociative Chemisorption on Metal Surfaces: H2 on Ag(111)

Ab initio nonadiabatic molecular dynamics investigations on the excited carriers in condensed matter systems

Contact Info

Product

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Evidence for Electron–Hole Pair Excitation in the Associative Desorption of H₂ and D₂ from Au(111)