Jump to main content
Jump to site search


Quantum chemical studies of redox properties and conformational changes of a four-center iron CO2 reduction electrocatalyst

Author affiliations

Abstract

The CO2 reduction electrocatalyst [Fe4N(CO)12] (abbrev. 1) reduces CO2 to HCO2 in a two-electron, one-proton catalytic cycle. Here, we employ ab initio calculations to estimate the first two redox potentials of 1 and explore the pathway of a side reaction involving CO dissociation from 13−. Using the BP86 density functional approximation, the redox potentials were computed with a root mean squared error of 0.15 V with respect to experimental data. High temperature Born–Oppenheimer molecular dynamics was employed to discover a reaction pathway of CO dissociation from 13− with a reaction energy of +10.6 kcal mol−1 and an activation energy of 18.8 kcal mol−1; including harmonic free energy terms, this yields ΔGsep = 1.4 kcal mol−1 for fully separated species and ΔG = +17.4 kcal mol−1, indicating CO dissociation is energetically accessible at ambient conditions. The analogous dissociation pathway from 12− has a reaction energy of 22.1 kcal mol−1 and an activation energy of 22.4 kcal mol−1Gsep = 12.8 kcal mol−1, ΔG = +18.1 kcal mol−1). Our computed harmonic vibrational analysis of [Fe4N(CO)11]3− or 23− reveals a distinct CO-stretching peak red-shifted from the main CO-stretching band, pointing to a possible vibrational signature of dissociation. Multi-reference CASSCF calculations are used to check the assumptions of the density functional approximations that were used to obtain the majority of the results.

Graphical abstract: Quantum chemical studies of redox properties and conformational changes of a four-center iron CO2 reduction electrocatalyst

Back to tab navigation

Publication details

The article was received on 06 Oct 2017, accepted on 27 Jan 2018 and first published on 29 Jan 2018


Article type: Edge Article
DOI: 10.1039/C7SC04342B
Citation: Chem. Sci., 2018, Advance Article
  • Open access: Creative Commons BY-NC license
  •   Request permissions

    Quantum chemical studies of redox properties and conformational changes of a four-center iron CO2 reduction electrocatalyst

    H. Jang, Y. Qiu, M. E. Hutchings, M. Nguyen, L. A. Berben and L. Wang, Chem. Sci., 2018, Advance Article , DOI: 10.1039/C7SC04342B

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Material from this article can be used in other publications provided that the correct acknowledgement is given with the reproduced material and it is not used for commercial purposes.

    Reproduced material should be attributed as follows:

    • For reproduction of material from NJC:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the Centre National de la Recherche Scientifique (CNRS) and the RSC.
    • For reproduction of material from PCCP:
      [Original citation] - Published by the PCCP Owner Societies.
    • For reproduction of material from PPS:
      [Original citation] - Published by The Royal Society of Chemistry (RSC) on behalf of the European Society for Photobiology, the European Photochemistry Association, and RSC.
    • For reproduction of material from all other RSC journals:
      [Original citation] - Published by The Royal Society of Chemistry.

    Information about reproducing material from RSC articles with different licences is available on our Permission Requests page.

Search articles by author

Spotlight

Advertisements