DigiElch8 Help

Topics

•Customizing the appearance of DigiElch

•Commands in the Menu Windows of the Ribbon Toolbar

•Opening an existing DigiElch 7/8 - Project stored in a dep - file

•Loading an existing "old-style" DigiElch 6 Document stored in a cvs - file

•Basic operations

•Saving  all open DigiElch 8 Documents in a DigiElch 8 - Project file

Topics

•Defining simple charge-transfer mechanism

•Specify the simulation parameters

•Running a simulation

•Adding/Removing Reaction Equations for heterogeneous charge-transfer reactions

•Adding/Removing Scan Segments

•Adding Reaction Equations for homogeneous chemical reactions

•Copy a Simulation and Paste it into another Simulation Document

•Copy & Paste Simulation Documents

•Running a CV-Simulation using different scan rates in the forward and backward scan

•Simulating the current response for a Thin-Layer Cell experiment and for a Rotating Disc electrode

•Options Diffusion:Semi-Infinite-1D, Finite, Semi-Infinite-2D, Hydrodynamic

•Clipboard commands: Copy, Paste

•Display commands: Zoom, Unzoom, Refresh Screen, Next, Previous

•Commands: Edit, Duplicate, Run, Circles, Filled Circles, Next Scan Segment, Min/Max Info

•Compute data from Min/Max Info, Plot Graph from Min/Max Info

Topics

•Plot Options for cyclic-voltammetric current curves

•Info and Options provided in the Properties-Window

Topics

•Comparison of Fixed Grid and Adaptive Grid simulations

•Show how Concentration Profiles alter in the course of the (simulated) experiment

•Setting/Removing a Break Point

•Commands: Pause, Export, Display Speed

•Customizing the color for plotting the Concentration Profiles of a particular species

Topics

•Run a simulation for a CT-Reaction comprising adsorbed species

•Show how Surface Concentrations alter in the course of the (simulated) experiment

•Show how Surface Coverage alters in the course of the (simulated) experiment

•Setting/Removing a Break Point

•Commands: Pause, Export, Display Speed

•Customizing the color for plotting the Surface Concentration/ Surface Coverage of a particular species

•Select distance in y-direction (parallel to electrode) to which the plotted Surface Concentrations refer in the case of a 2D-Simulation (e.g. micro-disk or micro-band electrode)

Topics

Using simulated CVs as target curves in a Data Fitting Project. CVs simulated for a simple charge-transfer mechanism are used to mimic real experimental CVs measured without IR-compensation. The uncompensated ohmic resistance is assumed to be Ru = 300 Ohm.
 

•Include a constant level of IR-Drop in a series of simulations executed for different scan rates

•Export all Simulations to RAM-Disc

•Re-Import the Simulations to mimic experimental CVs. The latter are used as target curves in a Data Fitting Project.

•Set uncompensated Ohmic resistance, Ru, equal to zero in all target curves.

•Run Fitting Procedure to find parameters matching the target curves in the optimal way if IR-Drop is neglected

Topics

Using ASCII-files exported by third-party electrochemical equipment as target curves in a Data Fitting Project. The target curves are real experimental CVs measured for a nickel(II)-chelate complex (denoted as NiL) in the absence and presence of dipyridine (denoted as DP).    

•Customizing a user-defined Import Filter

•Creating a template object for importing the ASCII-files

•Importing the ASCII-files

•Modify imported CVs by adding parameters (such as scan rate or species concentrations) which are specific for each individual experiment

•Save modified CVs as use-files or export them to RAM-Disc and save RAM-Disk content as RAM-Disk-file (file extension *.rmd).

•Define Mechanism and Starting Parameters used by the fitting procedure

•Run Data Fitting

Topics

Using the Global Minimum Finder to detect parameter couplings and superfluous reactions

•A series of CVs simulated for a reversible charge transfer process accompanied by a fast irreversible follow-up reaction is used to mimic experimental target curves (ErevCirrev- mechanism). For this purpose, the scan rate used in these simulations varies from 1 to 30 V/s and a constant (relative) level of noise was added to each CV.

•If the follow-up reaction is very there is a (well-known) perfect coupling between the standard potential of the CT-reaction and the rate constant of the homogeneous reaction that cannot be unraveled mathematically. Consequently, subjecting CVs for this kind of mechanism to Data Fitting could lead to unpredictable results if the parameter coupling is not recognized

•In the presented example the analysis of the "experimental" CVs is studied on the basis of a mechanism comprising not only the both reactions actually involved in the ErevCirrev - mechanism but also another follow-up reaction which has no effect on the simulated current curve. This is done to demonstrate the difference between a "superfluous" reaction and a reaction which is absolutely necessary to make the fit working at all even if the "correct" thermodynamic and/or kinetic parameters cannot be determined in some kind of way.  

Topics

•Running a series of FT-CV simulations for an EC-mechanism

•Demonstrating the plotting options

•Exporting the FT-CV simulations to the RAM-Disk

•Re-Importing the FT-CVs to use them as target curves in a Data Fitting Project

•Defining the starting parameters for the fitting procedure and selecting the parameters to be optimized

•Run data fitting by fitting the second-harmonic AC current component

•Re-run data fitting by fitting the envelope of the third harmonic AC current component

•Using the Global Minimum Finder for getting good starting parameters

Topics

•Running a (multi-sine) impedance simulation for a second-order catalytic mechanism

•Using the Duplicate-command for displaying a series of simulations covering a wide frequency range

•Demonstrating Plot-Options and Color Settings

•Modifying the default noise signal

•Plotting the Screen Info as Graphics

•Watching the simulated concentration profiles and/or surface concentrations

Topics

•Importing impedance data stored in use-file format.

•Dealing with Info required for Data Fitting but not stored in the ASCII-File

•Defining mechanism and starting parameters

•Selecting parameters for being optimized by the fitting procedure

•Run Data Fitting using experiments not corrected for IR-drop and double layer effects

•Applying Background Correction before starting the fitting procedure

•Show Difference between Background Correction and addition of Ru/Cdl-values to (or removal of Ru/Cdl-values from) imported experiments

Topics

•Connect Potentiostat and Edit Experimental and Instrumental Parameters

•Run a CV-Experiment without IR-Compensation

•Measure the uncompensated Ohmic Resistance

•Re-Run Experiment with IR-Compensation

•Optimizing the dynamic Properties of the Potentiostat

•Run CA-, SW-, FT-CV and Multi-Sine - Impedance (IMP-) Experiments

Topics

•Continuation of the experiments shown in Part I

•Run a series of CV-Experiments using different scan rates

•Apply Background Correction by subtracting the experimentally measured background current

•Use background-corrected CVs directly for Data Fitting