Atomistic modeling of conduction and transport processes in micro-porous electrodes containing Nafion electrolytes

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Atomistic modeling and/or experimental methods were conducted to study transport processes in the porous electrodes of polymer electrolyte fuel cells (PEFCs) and of mediator enhanced polymer electrolyte supercapacitors (MEPESCs). The simulations show that vibrations of the Pt nanocrystallines on rhe carbon supports significantly impacts diffusion in the Nafion electrolyte clusters between the carbon supports and enhances the diffusivity of hydrogen, oxygen, methanol, water, and hydronium up to 8 times the nominal value Charging the carbon support alters the diffusivities. It was visualized that charging of Pt nanocrystallines resulted in disintegration of the Pt catalysts leading to a reduction in catalytic activity of the catalyst layer. Re-precipitation and re- crystallization of the Pt under a full discharging condition can also be visualized using the molecular dynamics (MD) modeling method. MD simulations also indicate that the mobility of the iodine mediators is at least 10 times greater than other small ions in the Nafion electrolyte. The degradation of the MEPESC is dominated by the crossover of I ions but not I2 in Nafion.

Original languageEnglish (US)
Title of host publicationProceedings of the ASME Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009
Pages253-258
Number of pages6
DOIs
StatePublished - Jul 12 2010
EventASME 2009 Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009 - Shanghai, China
Duration: Dec 18 2009Dec 21 2009

Publication series

NameProceedings of the ASME Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009
Volume2

Other

OtherASME 2009 Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009
CountryChina
CityShanghai
Period12/18/0912/21/09

    Fingerprint

Keywords

  • Atomistic modeling
  • PEFC
  • Porous electrode
  • Supercapacitor

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes

Cite this

Zhou, X. (2010). Atomistic modeling of conduction and transport processes in micro-porous electrodes containing Nafion electrolytes. In Proceedings of the ASME Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009 (pp. 253-258). (Proceedings of the ASME Micro/Nanoscale Heat and Mass Transfer International Conference 2009, MNHMT2009; Vol. 2). https://doi.org/10.1115/MNHMT2009-18116