Dear friend Domenico Dalessandro

It is possible to perform cyclic voltammetry (CV) on a PEM electrolytic cell without using a reference electrode, but it may be more challenging to accurately determine the potential values.

Without a reference electrode, the potential of the working electrode is not known with respect to a standard reference point. One solution to this problem is to use a pseudo-reference electrode, which is a working electrode made of a material that undergoes a reversible redox reaction at a known potential, and which serves as an internal reference electrode. However, this requires careful selection of the pseudo-reference material and can be difficult to implement in a PEM electrolytic cell.

Another option is to use a three-electrode setup with a separate reference electrode outside the cell and connected to the working electrode via a salt bridge. However, this may not be practical if the cell is sealed or if the reference electrode cannot be positioned close enough to the working electrode.

In the absence of a reference electrode, the ECSA (electrochemically active surface area) can still be calculated from the CV data using the double-layer capacitance (Cdl) method. This involves measuring the capacitance of the electrochemical double layer at the electrode surface, which is related to the surface area. However, this method requires accurate determination of the potential values, so care must be taken to ensure that the potential scale is consistent across measurements.

Overall, while it is possible to perform CV on a PEM electrolytic cell without a reference electrode, it may be more challenging to obtain accurate results.

Here are some references related to your question:

1. Gileadi, E., Electrode Kinetics for Chemists, Chemical Engineers and Materials Scientists, 1st Edition, Wiley, 1993.

2. Bard, A.J. and Faulkner, L.R., Electrochemical Methods: Fundamentals and Applications, 2nd Edition, Wiley, 2001.

3. Eftekhari, A., Cyclic Voltammetry: Simulation and Analysis of Reaction Mechanisms, 1st Edition, CRC Press, 2018.

4. Compton, R.G., Banks, C.E., Understanding Voltammetry, 2nd Edition, Imperial College Press, 2011.

5. Koper, M.T.M., "Theory of Cyclic Voltammetry for Surface-Confined Redox Reactions," The Journal of Physical Chemistry B, Vol. 110, No. 39, 2006, pp. 19598-19603.

These references cover a range of topics related to cyclic voltammetry, including theory, instrumentation, and applications. They may be helpful in providing more detailed information on calculating ECSA and conducting cyclic voltammetry experiments without a reference electrode.