Molecular Electron-Transfer in Systems Relevant to Geological Sciences: Transport and Electrochemical Reactions in Compartments

• Applicant: Professor Dr. Bernd Speiser
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management
• Term: from 2004 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5470602

• Final Report Year: 2011

Final Report Abstract

A model for liquid/liquid phase boundaries (NAPLs) based on scanning electrochemical microscope (SECM) techniques and immiscible liquids was investigated. Approach curves of (ultra-) microelectrodes to coal tar of various ageing states show distinctly different behavior. Simulation of electrochemical processes was extended to equilibrium processes (infinitely fast kinetics) by application of Lagrange multiplier formulations. Objectoriented implementation of this approach within the open-source EChem++ problem solving environment allows its use with cyclic voltammetric and chronoamperometric conditions. Furthermore, an advantageous direct control of the current error in electrochemical finite element simulations was achieved, which guarantees the estimated error of both concentrations and the experimentally accessible quantity current to be below a given limit.

Publications

• J. Electroanal. Chem. 608, 102-110 (2007)
  K. Ludwig, I. Morales and B. Speiser
  
• J. Electroanal. Chem. 608, 91-101 (2007)
  K. Ludwig and B. Speiser
  
• Simulation of Dirichlet-like Boundary Conditions by Lagrange Multipliers, 5th ECHEMS Meeting, Weingarten, Germany, June 2009
  S. Benthin and B. Speiser
  
• Simulation of Equilibrium Electron-Transfer Processes in Electrochemical Reaction-Diffusion Systems by Lagrange Multipliers, Electrochemistry 2010, Bochum, Germany, September 2010
  S. Benthin and B. Speiser