Abstract
We report the results of ab initio molecular dynamics simulations of a model Nafion polymer membrane initially equilibrated using classical molecular dynamics simulations. We studied three hydration levels (λ) of 3, 9, and 15 H2O/SO3 - corresponding to dry, hydrated, and saturated fuel cell membrane, respectively. The barrier for proton transfer from the SO3 --H3O+ contact ion pair to a solvent-separated ion pair decreased from 2.3 kcal/mol for λ = 3 to 0.8 kcal/mol for λ = 15. The barrier for proton transfer between two water molecules was in the range from 0.7 to 0.8 kcal/mol for the λ values studied. The number of proton shuttling events between a pair of water molecules is an order of magnitude more than the number of proton hops across three distinct water molecules. The proton diffusion coefficient at λ = 15 is about 0.9 × 10-5 cm2/s, which is in good agreement with experiment and our previous quantum hopping molecular dynamics simulations.
| Original language | English |
|---|---|
| Pages (from-to) | 16522-16529 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry B |
| Volume | 117 |
| Issue number | 51 |
| DOIs | |
| Publication status | Published - Dec 27 2013 |
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ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Materials Chemistry
- Surfaces, Coatings and Films
Cite this
Ab initio molecular dynamics simulation of proton hopping in a model polymer membrane. / Devanathan, Ram; Idupulapati, Nagesh; Baer, Marcel D.; Mundy, Christopher J.; Dupuis, Michel.
In: Journal of Physical Chemistry B, Vol. 117, No. 51, 27.12.2013, p. 16522-16529.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ab initio molecular dynamics simulation of proton hopping in a model polymer membrane
AU - Devanathan, Ram
AU - Idupulapati, Nagesh
AU - Baer, Marcel D.
AU - Mundy, Christopher J.
AU - Dupuis, Michel
PY - 2013/12/27
Y1 - 2013/12/27
N2 - We report the results of ab initio molecular dynamics simulations of a model Nafion polymer membrane initially equilibrated using classical molecular dynamics simulations. We studied three hydration levels (λ) of 3, 9, and 15 H2O/SO3 - corresponding to dry, hydrated, and saturated fuel cell membrane, respectively. The barrier for proton transfer from the SO3 --H3O+ contact ion pair to a solvent-separated ion pair decreased from 2.3 kcal/mol for λ = 3 to 0.8 kcal/mol for λ = 15. The barrier for proton transfer between two water molecules was in the range from 0.7 to 0.8 kcal/mol for the λ values studied. The number of proton shuttling events between a pair of water molecules is an order of magnitude more than the number of proton hops across three distinct water molecules. The proton diffusion coefficient at λ = 15 is about 0.9 × 10-5 cm2/s, which is in good agreement with experiment and our previous quantum hopping molecular dynamics simulations.
AB - We report the results of ab initio molecular dynamics simulations of a model Nafion polymer membrane initially equilibrated using classical molecular dynamics simulations. We studied three hydration levels (λ) of 3, 9, and 15 H2O/SO3 - corresponding to dry, hydrated, and saturated fuel cell membrane, respectively. The barrier for proton transfer from the SO3 --H3O+ contact ion pair to a solvent-separated ion pair decreased from 2.3 kcal/mol for λ = 3 to 0.8 kcal/mol for λ = 15. The barrier for proton transfer between two water molecules was in the range from 0.7 to 0.8 kcal/mol for the λ values studied. The number of proton shuttling events between a pair of water molecules is an order of magnitude more than the number of proton hops across three distinct water molecules. The proton diffusion coefficient at λ = 15 is about 0.9 × 10-5 cm2/s, which is in good agreement with experiment and our previous quantum hopping molecular dynamics simulations.
UR - http://www.scopus.com/inward/record.url?scp=84891429942&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84891429942&partnerID=8YFLogxK
U2 - 10.1021/jp410229u
DO - 10.1021/jp410229u
M3 - Article
C2 - 24320080
AN - SCOPUS:84891429942
VL - 117
SP - 16522
EP - 16529
JO - Journal of Physical Chemistry B Materials
JF - Journal of Physical Chemistry B Materials
SN - 1520-6106
IS - 51
ER -