Hi,

I hope you have done ORR by means of CV. The exchange current density can be obtained from Tafel plot (log I vs. V, then extrapolate current to V  = 0). In that case you will have to do LSV rather than CV. The magnitude of exchange current density is measure of rate of reaction. Higher the ECD faster is the reaction rate. I am not sure the peak current in CV will serve this purpose.

Hi,

I hope you have done ORR by means of CV. The exchange current density can be obtained from Tafel plot (log I vs. V, then extrapolate current to V  = 0). In that case you will have to do LSV rather than CV. The magnitude of exchange current density is measure of rate of reaction. Higher the ECD faster is the reaction rate. I am not sure the peak current in CV will serve this purpose.

At first I would like to thanking you for your response. Actually I did the cv and RDE. I have to calculate the ECD from the RDE data at a particular rpm.

In that case please look for 'Levich equation' in the literature.

I have also prepared the Kl plot.

Hi

You can calculate exchange current density from RDE data. Initially construct a tafel plot from you RDE ( potential vs mass transfer corrected current). convert you potential to RHE. Extrapolate it to slope to zero and note the corresponding io. That gives you the exchange current density. or else you can calculate from tafel equation too. for more information follow this link...

http://pubs.rsc.org/en/content/articlelanding/2015/cy/c4cy01001a#!divAbstract

good luck