New Research In
Articles by Topic
- Agricultural Sciences
- Applied Biological Sciences
- Biophysics and Computational Biology
- Cell Biology
- Developmental Biology
- Environmental Sciences
- Immunology and Inflammation
- Medical Sciences
- Plant Biology
- Population Biology
- Psychological and Cognitive Sciences
- Sustainability Science
- Systems Biology
广东福利彩票管理中心:Reaction intermediates during operando electrocatalysis identified from full solvent quantum mechanics molecular dynamics
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
The gap preventing a direct comparison between experiment and atomic simulation still exists due to the unrealistic consideration of the operando experimental condition in commonly used quantum mechanics (QM). In this work, we advanced the QM-based simulation of the electrode–electrolyte interface with explicit consideration of solvent and applied voltage to produce reactive trajectories as input for a two-phase thermodynamics model in generating vibrational density of states that can be directly compared with the reported experimental spectroscopy. After resolving the signals, we successfully distinguished the reactive intermediates in a carbon dioxide reduction reaction, which provides an atomic-scale understanding of this important reaction.
Electrocatalysis provides a powerful means to selectively transform molecules, but a serious impediment in making rapid progress is the lack of a molecular-based understanding of the reactive mechanisms or intermediates at the electrode–electrolyte interface (EEI). Recent experimental techniques have been developed for operando identification of reaction intermediates using surface infrared (IR) and Raman spectroscopy. However, large noises in the experimental spectrum pose great challenges in resolving the atomistic structures of reactive intermediates. To provide an interpretation of these experimental studies and target for additional studies, we report the results from quantum mechanics molecular dynamics (QM-MD) with explicit consideration of solvent, electrode–electrolyte interface, and applied potential at 298 K, which conceptually resemble the operando experimental condition, leading to a prototype of operando QM-MD (o-QM-MD). With o-QM-MD, we characterize 22 possible reactive intermediates in carbon dioxide reduction reactions (RRs). Furthermore, we report the vibrational density of states (v-DoSs) of these intermediates from two-phase thermodynamic (2PT) analysis. Accordingly, we identify important intermediates such as chemisorbed (), *HOC-COH, *C-CH, and *C-COH in our o-QM-MD likely to explain the experimental spectrum. Indeed, we assign the experimental peak at 1,191 cm?1 to the mode of C-O stretch in *HOC-COH predicted at 1,189 cm?1 and the experimental peak at 1,584 cm?1 to the mode of C-C stretch in *C-COD predicted at 1,581 cm?1. Interestingly, we find that surface ketene (*C=C=O), arising from *HOC-COH dehydration, also shows signals at around 1,584 cm?1, which indicates a nonelectrochemical pathway of hydrocarbon formation at low overpotential and high pH conditions.
- ?1To whom correspondence should be addressed. Email: .
Author contributions: T.C. and W.A.G. designed research; T.C. and A.F. performed research; T.C. and W.A.G. analyzed data; and T.C., A.F., and W.A.G. wrote the paper.
Reviewers: S.H.-S., Yale University; P.S., University of California, Los Angeles; and R.J.S., University of California, Berkeley.
The authors declare no conflict of interest.
See Commentary on page 7611.
This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1821709116/-/DCSupplemental.
Published under the PNAS license.