Molecular Modeling of Electrocatalysis Perla B' Balbuena, University of South Carolina balbuenaengr'

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Molecular Modeling of ElectrocatalysisPerla B.
Balbuena, University of South Carolina
(balbuena_at_engr.sc.edu)
DOD-EPSCoR

• Goals
• Develop and apply theoretical procedures for
  understanding the fundamentals of
  electrocatalytic mechanisms
• Atomistic level characterization of
  electroreduction of oxygen on platinum catalysts
• Use of atomistic level characterization for
  prediction of oxygen electroreduction macroscopic
  properties to be compared with electrochemical
  experiments
• Guide the design of effective electrocatalysts.

• Accomplishments
• Established a systematic procedure to analyze an
  electrocatalytic problem.
• Demonstrated the main effects due to electron and
  proton transfer in the rate-determining step of
  O2 electroreduction on Pt.
• Explored the shape and mobility of platinum and
  bimetallic nanoclusters supported on graphite,
  exposed to various gases.
• Investigated the four-electron electroreduction
  of oxygen on Pt (111). The resultant surface
  composition as a function of overpotential
  elucidates the roles of adsorbed H2O and OH.

• Scientific/Technical Approach
• Prediction of electronic, thermodynamic, and
  kinetic properties for adsorption and
  dissociation of molecular oxygen on platinum, and
  proton transfer to the adsorbed oxygen, using
  modern density functional methods.
• Prediction of structure and dynamics of platinum
  nanoclusters deposited on graphite substrates
  using molecular dynamics simulations.
• Prediction of cyclic voltammograms as a function
  of overpotential based on a sequence of electron
  and proton transfer reactions on a platinum
  surface, using dynamic Monte Carlo simulations.