Electrochemical ORR reaction fit tools in Python

Overview

ORR reaction is one of the most important of all electrochemical reactions. Unfortunately, experimental research of this reaction is really complicated due to lack of standardization and processing data time involved.

This project aims to provide quick-tools developed in Python for ORR data treatment. These tools are based on data acquisition recommendations described in the Kocha et. al. 2017 . Main tools consist in obtain following parameters:

• Stacked plots associated to nitrogen analysis.
• Stacked plots associated to oxygen analysis.
• Stacked plots associated to ORR analysis.
• Redox peak potential at 0 rpm.
• Koutecky-levich plots (linealiced).
• Bode and Nyquist plots for nitrogen (0 rpm, 1000 rpm and 2000 rpm) and oxygen (1600 rpm) experiments.
• Resistivity (Ω) associated to EIS for nitrogen (0 rpm, 1000 rpm and 2000 rpm) and oxygen (1600 rpm) experiments.
• Number of electrons involved in ORR.
• Limiting current at 0.2 Volts vs RHE
• Onset potential for 0.1 mA/cm2 for ORR.
• Halfway potential for ORR.

ORR reaction in electrochemistry

Oxygen reduction reaction (ORR) is also the most important reaction in life processes. In aqueous media occurs mainly by two pathways: the direct 4-electron reduction pathway from O₂ to H₂O, and the 2-electron reduction pathway from O₂ to hydrogen peroxide (H₂O₂).

ORR reaction in the laboratory

Most common technique for ORR studies is cyclic voltammetry using a rotating disk electrode (RDE), and rotating ring-disk electrode (RRDE). Here I used experimental protocol described in readme_experimental_protocol.md and provide an example of kind of data and results obtained by this project in the folder carbon_superP.

Python modules required for running script

Prior to run the ORR script, install following python packages

Matplotlib

python -m pip install -U pip
python -m pip install -U matplotlib

Numpy

pip install numpy

Pandas

pip install pandas

Glob

pip install glob3

Shutil

pip install pytest-shutil   

Astropy

pip install astropy

Bibliography

Song C., Zhang J. (2008) Electrocatalytic Oxygen Reduction Reaction. In: Zhang J. (eds) PEM Fuel Cell Electrocatalysts and Catalyst Layers. Springer, London.

Kocha, S.S., Shinozaki, K., Zack, J.W. et al. Best Practices and Testing Protocols for Benchmarking ORR Activities of Fuel Cell Electrocatalysts Using Rotating Disk Electrode. Electrocatalysis 8, 366–374 (2017).

Additional coments

The Electrochemical ORR reaction fit tools in the Python version are still in it's beta state. This means that it can have some bugs and issues. However, testing and contributing is very welcome.

Contributors

gcarrascohuertas