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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: JamminMic on February 10, 2019, 12:34:55 PM

Title: Finding an Open Circuit Potential of a Hydrogen Pump Problem
Post by: JamminMic on February 10, 2019, 12:34:55 PM
My problem is:

"In an electrochemical H2-pump using a proton conductive membrane (pH ≈ 0), H2 can be compressed from low to high pressure. Assume an exchange current density of the HOR/HER on Pt of i0 = 100 mA cm-2 Pt with αa = αc (charge transfer coefficient) = 0.5, a H2-partial pressure of 100 kPa on the low and 1000 kPa on the high pressure side. The system is operated at 80 °C and the roughness factor of the electrodes is 100 cm2Pt cm-2. The HFR (High Frequency Resistance) was determined to be 50 mΩ cm2."

"What is the thermodynamic open circuit potential between the two electrodes?"

I have tried using Butler-Volmer or a Tafel Slope equation in order to find the Overpotential but I'm not really getting anywhere. I'm also guessing that Nernst may be involved. Any suggestions?