You can integrate the adsorption-desorption peak from CV (around 0 to 0.3 V Vs RHE), it will be the charge of the double-layer, then divide by the scan rate and use the relation: 1 square cm of ECSA is equal to 210X10-6C (Coulomb) [1cm2/210X10-6C]. After that, you can divide by miligrams of your sample. Also you can obtain the electrochemical active surface area from EIS spectra using the limiting capacitance.

you must integrate the surface of the reduction peak  and compare it to  the surface of a square

thank you for your answer. can you please elaborate what does 'the surface a square' means? In our case we have integrated the area for the reduction peak.

You can integrate the adsorption-desorption peak from CV (around 0 to 0.3 V Vs RHE), it will be the charge of the double-layer, then divide by the scan rate and use the relation: 1 square cm of ECSA is equal to 210X10-6C (Coulomb) [1cm2/210X10-6C]. After that, you can divide by miligrams of your sample. Also you can obtain the electrochemical active surface area from EIS spectra using the limiting capacitance.

Sure, you must only integrate the current in the H adsorption potential region. Surface coverage of H and SO4- is well stablished on Pt polycrystalline and single crystal surfaces (Check the works published by Feliu et.al. and Cuesta A. et.al).

Just compare the charge density per centimeter square given in the literature for these Pt surfaces (I guess it will fit better the pollycrystalline surfaces to your experiments) with your integrated charge value, then you will obtain the cm2 of your Pt surface. Please, take care that this correspond only to Pt surface area and it is not included the bulk Pt (inside the particles). When you weigh your Pt catalyst it is included not only the Pt surface atoms but also the bulk Pt in your catalyst particles. This would serve you as an estimation of the average particle size when comparing the total volumen of Pt catalyst (0.01 mg/Pt density) and the Pt surface active area you determined by electrochemical means.

I hope this information can help you. Good luck.

Kind regards

Dear Daniel,

Could you please explain how to calculate ECSA from EIS spectra? You may suggest a source for reference. Thank you.

Hi, Dr. Tamilarasan,

you could download this article: 

http://www.sciencedirect.com/science/article/pii/S0013468604010758

Fig 6 and Fig 8, may help you to understand how determinate the limiting capacitance from the EIS data, after that, you can use the relation 0.196 mFcm-2 of Pt to determinate the ECSA. Notice, this relation is for platinum electrodes.  

Regards!

Daniel

You may go throw the EC Lab electro chemical software. it is very helpfull and easily you can calculate ECSA by integration of plots.

You can read an experiment done by EC lab here" https://www.bio-logic.net/wp-content/uploads/20101105-application-note-11.pdf"