Imaging covalent bond formation by H atom scattering from graphene
Abstract
Viewing the atomic-scale motion and energy dissipation pathways involved in forming a covalent bond is a longstanding challenge for chemistry. We performed scattering experiments of H atoms from graphene and observed a bimodal translational energy loss distribution. Using accurate first-principles dynamics simulations, we show that the quasi-elastic channel involves scattering through the physisorption well where collision sites are near the centers of the six-membered C-rings. The second channel results from transient C–H bond formation, where H atoms lose 1 to 2 electron volts of energy within a 10-femtosecond interaction time. This remarkably rapid form of intramolecular vibrational relaxation results from the C atom's rehybridization during bond formation and is responsible for an unexpectedly high sticking probability of H on graphene.
Additional Information
© 2019 American Association for the Advancement of Science. Received 16 January 2019; accepted 6 March 2019. We thank D. Auerbach and D. Schwarzer for helpful discussions. Funding: H.J., O.B., and A.M.W. acknowledge support the from the SFB1073 under project A04, from the Deutsche Forschungsgemeinschaft (DFG) and financial support from the Ministerium für Wissenschaft und Kultur (MWK) Niedersachsen, and the Volkswagenstiftung under grant INST 186/902-1 to build the experimental apparatus. A.M.W., M.K., and A.K. also acknowledge the Max Planck Society for the Advancement of Science. F.D. and T.F.M. acknowledge that this material is based on work performed by the Joint Center for Artificial Photosynthesis, a U.S. Department of Energy (DOE) Energy Innovation Hub, supported through the Office of Science of the DOE under award DE-SC0004993. T.F.M. and F.R.M. acknowledge joint support from the DOE (award DE-SC0019390). F.R.M. is grateful to the Engineering and Physical Sciences Research Council for funding (EP/M013111/1). Author contributions: H.J. carried out experiments, analyzed experimental data and contributed to the manuscript. M.K. participated in the MD and RPMD code development, fit the EMFT data to a REBO potential, carried out molecular dynamics calculations, and contributed to the manuscript. Y.D. assisted with experiments. F.D. contributed to the EMFT code, carried out the EMFT calculations, and contributed to the manuscript. F.R.M. contributed to the EMFT code. A.K. directed the molecular dynamics work, developed the MD code, and contributed to the manuscript. A.M.W. conceived the experiment and wrote the paper. T.F.M. directed the electronic structure work, contributed to the EMFT code, and contributed to the manuscript. O.B. built and commissioned the Rydberg tagging apparatus, conceived and supervised experimentation, and contributed to the manuscript. Competing interests: None declared. Data and materials availability: The PES is archived at github.com/akandra/md_tian2/blob/master/src/pes_rebo_mod.f90. There are no restrictions on materials used in this work. All data needed to evaluate the conclusions in the paper are present in the paper or the supplementary materials.Attached Files
Supplemental Material - aaw6378-Jiang-SM.pdf
Supplemental Material - aaw6378s1.mov
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Additional details
- Eprint ID
- 94977
- DOI
- 10.1126/science.aaw6378
- Resolver ID
- CaltechAUTHORS:20190425-132430583
- SFB1073
- Deutsche Forschungsgemeinschaft (DFG)
- Ministerium für Wissenschaft und Kultur (MWK)
- INST 186/902-1
- Volkswagenstiftung
- Max Planck Society
- DE-SC0004993
- Department of Energy (DOE)
- DE-SC0019390
- Department of Energy (DOE)
- EP/M013111/1
- Engineering and Physical Sciences Research Council (EPSRC)
- Created
-
2019-04-25Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field
- Caltech groups
- JCAP