Density Functional Theory Molecular Dynamics Studies on Hydrated Clusters of Carbon Dioxide Radical Anion

Research output: Conference PapersRGC 33 - Other conference paperpeer-review

View graph of relations

Related Research Unit(s)

Detail(s)

Original languageEnglish
Publication statusPresented - 24 Feb 2021

Conference

Title21st International Union of Materials Research Societies- International Conference in Asia (IUMRS-ICA 2020)
LocationOnline
PlaceThailand
CityChiang Mai
Period23 - 26 February 2021

Abstract

Carbon dioxide radical anion (CO2•-) is an important intermediate involved in electrochemical reduction of carbon dioxide. IR spectroscopic studies of hydrated clusters of CO2•- (i.e. [CO2(H2O)n]-) in gas phase had demonstrated a blueshift in C–O symmetric stretch frequencies of these clusters as the cluster size increased, but the molecular picture behind such size-dependence has yet to be explored. This work employed density functional theory molecular dynamics (DFT-MD) simulations to explore the underlying structural features and their corresponding theoretical IR spectra of [CO2(H2O)n]- clusters from n=0 up to n=8. Using the CP2K package, equilibration and subsequent dipole moment sampling were performed in NVT ensembles at 100 K using the revPBE functional as the underlying electronic structure method. The sampled time-dependent dipole moment data were autocorrelated and Fourier transformed to obtain the corresponding theoretical IR spectra. Two classes of structures have been identified at each cluster size, namely, “CH structures”, which contained hydrogen-bond solvation at the C atom of the radical anion, and “OH structures”, which did not contain such type of solvation. Among the two types of structures, CH structures showed a more prominent C–O symmetric stretch as compared to their OH counterparts at each cluster size and has also displayed a size-dependent blueshift in the corresponding IR band with increasing cluster size, which was consistent with experimental observations. This study had shed light on the structures of hydrated CO2•- clusters, which may hopefully lead to further understanding of the chemistry and reactivity patterns of CO2•- in aqueous environment and facilitate the future development of feasible protocols for CO2 utilization through reductive means.

Research Area(s)

  • CO2 activation, DFT molecular dynamics, CO2 radical anion, Hydrated clusters, Excess electron

Citation Format(s)

Density Functional Theory Molecular Dynamics Studies on Hydrated Clusters of Carbon Dioxide Radical Anion. / Lam, Zachary; Tang, Wai Kit; Siu, Chi-Kit.
2021. 21st International Union of Materials Research Societies- International Conference in Asia (IUMRS-ICA 2020), Chiang Mai, Thailand.

Research output: Conference PapersRGC 33 - Other conference paperpeer-review