BEGIN:VCALENDAR VERSION:2.0 PRODID:-//jEvents 2.0 for Joomla//EN CALSCALE:GREGORIAN METHOD:PUBLISH BEGIN:VEVENT UID:6cb9caa18a2a7873141b7b7b89d55e43 CATEGORIES:Colloquium CREATED:20220728T150654 SUMMARY:Professor Charles Musgrave, University of Colorado, Boulder DESCRIPTION:
More Accurate Modeling of Electrochemistry Us ing Grand Canonical Quantum Chemistry
Including the applied potential in quantum chemical models of electr ochemical processes is challenging. Early attempts avoided this challenge b y altogether ignoring the applied potential, but this neclects the central role played by the applied bias in driving electrochemistry. Later efforts approximated the effects of the applied bias on the energetics of the react ion using the elegant Computational Hydrogen Electrode model, which shifts the free energies of intermediates that react by the addition or removal of a proton and electron pair. However, this approximation fails for many cas es, especially those where the field changes the geometry of a reacting ads orbate, the electronic structure of the reactive site and where the interme diate steps are not equivalent to a transfer of an electron-proton pair.
In this talk I will describe the results o f using grand canonical density functional theory (GC-DFT), which explicitl y includes the applied potential, to model several electrocatalytic process es, including ammonia synthesis by biomimetic Chevrel phase materials [1], and CO2 reduction by single transition metal nitrogen doped graphene [2], m etal phosphides [3] and metals [4]. I will compare our results to those of the CHE model and to experiment. In each case we find that GC-DFT provides a richer and more accurate picture of electrochemistry, which is not only n ecessary for more fully understanding these complex processes, but which al so enables quantum chemists to rationally design new electrocatalysts.
< p style="text-align: justify;">[1] Singstock, R.R., and C. B. Musgrave, “Ho w the Bio-Inspired Fe2Mo6S8 Chevrel Breaks Electrocatalytic Nitrogen Reduct ion Scaling Relations,” Journal of the American Chemical Society, 144 (28), 12800-12806 (2022). DOI: 10.1021/jacs.2c03661Hosted by Professo r Charles Dismukes
Hybrid seminar: On-site location
is CCB-1303; for Zoom meeting information, please contact Loretta Lupo at&n
bsp;
More Accurate Mod eling of Electrochemistry Using Grand Canonical Quantum Chemistry< /p>
Including the applied potential in quant um chemical models of electrochemical processes is challenging. Early attem pts avoided this challenge by altogether ignoring the applied potential, bu t this neclects the central role played by the applied bias in driving elec trochemistry. Later efforts approximated the effects of the applied bias on the energetics of the reaction using the elegant Computational Hydrogen El ectrode model, which shifts the free energies of intermediates that react b y the addition or removal of a proton and electron pair. However, this appr oximation fails for many cases, especially those where the field changes th e geometry of a reacting adsorbate, the electronic structure of the reactiv e site and where the intermediate steps are not equivalent to a transfer of an electron-proton pair.
In this talk I will describe the results of using grand canonical density functional theo ry (GC-DFT), which explicitly includes the applied potential, to model seve ral electrocatalytic processes, including ammonia synthesis by biomimetic C hevrel phase materials [1], and CO2 reduction by single transition metal ni trogen doped graphene [2], metal phosphides [3] and metals [4]. I will comp are our results to those of the CHE model and to experiment. In each case w e find that GC-DFT provides a richer and more accurate picture of electroch emistry, which is not only necessary for more fully understanding these com plex processes, but which also enables quantum chemists to rationally desig n new electrocatalysts.
[1] Singstock, R
.R., and C. B. Musgrave, “How the Bio-Inspired Fe2Mo6S8 Chevrel Breaks Elec
trocatalytic Nitrogen Reduction Scaling Relations,” Journal of the Amer
ican Chemical Society, 144 (28), 12800-12806 (2022). DOI: 10.1021/jacs
.2c03661
[2] Brimley, P., A. Hussain, A. Alherz, Z. Bare, Y. Alsunni,
W. Smith, and C. Musgrave, “The Effect of the Applied Potential on the
Electrochemical Reduction of CO2 to CO over MN4C
Electrocatalysts Using Grand-Canonical Density Functional heory,”
ACS Catalysis, 12, 10161-10171 (2022). DOI: 10.1021/jacs.2c03661
[3] Calvinho, K., K. Yap, A. Alherz, A. Laursen, S. Hwang, Z. Bare, C. Musg
rave*, G. Dismukes*, “Surface Hydrides on Fe2P Electrocatalyst Reduce CO2&n
bsp;at Low Overpotential: Steering Selectivity to Ethylene Glycol,” Jou
rnal of the American Chemical Society, 143 (50) 21275-21285 (2021). DO
I: 10.1111/jace.18310
[4] Alsunni, Y., A. Alherz, Z. Bare, C. Musgrave
, “Electrocatalytic Reduction of CO2 to CO over Ag(110) and Cu(211) Mo
deled by Grand-Canonical Density Functional Theory,” Journal of Physica
l Chemistry C, 125 (43) 23773-23783 (2021). DOI: 10.1021/acs.jpcc.1c07
484
Hosted by Professor Charles Dismukes