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?