How to compare the activities of two different water oxidation catalysts is not solved problem. What are the criteria? In most of publications the dioxygen formation is not proved. First, you need to prove that dioxigen is formed.

I recommend to use same potiential window for CV measurement. Although we need the increment of non-faradaic current depending on scan rate to obtain "EDL" value, sometimes we can see the change of EDL value by different potential window.

Furthermore, if you want to compare Active surface area in different types of catalysts, you have to calculate ECSA rather than EDL value.

There is two step to meausre "ECSA".

First, we measure "EDL" value of each catalyst by CV measurement under non-faradaic region (maybe you did), and then we can divide every EDL value by specific capacitance of each catalyst for obtaining "ECSA" value.

Only "ECSA" value divided by specific capacitance could be utilized for different types of catalysts.

Please check below paper.

J. Am. Chem. Soc. 2013, 135, 45, 16977–16987

Thanks

Thank you Sanghyun Bae , I completely agree with your response. of course, my intentions was to calculate ECSA. however, as you probably know, the CV is taken within a non-faradaic potential window. my confusing was wether to use same non-faradaic window for all the catalyst or determine individually the appropriate widow for each catalyst.