Theoretical questions 2018

Pagina 1

ECCS – Examples of theory questions Basic (students must know to pass the exam) 1. Draw the electrical potential in the double layer for a HOR in equilibrium 2. Draw the electrical potential in the double layer for a ORR in equilibrium 3. Is 𝜑"#$−𝜑#& positive or negative for HOR in equilibrium in a PEMFC? Why? 4. Is 𝜑"#$−𝜑#& positive or negative for ORR in equilibrium in a PEMFC? Why? 5. Write the Nernstian equilibrium potential for an electrochemical cell based on H2/O2 as a function of chemical activities 6. Is the electrode overpotential positive or negative when HOR occurs? Why? 7. Is the electrode overpotential positive or negative when ORR occurs? Why? 8. Write the Butler-Volmer kinetics equation for HOR 9. Write the Tafel equation for ORR 10. Write an equation for electroneutrality in a generic electrolyte 11. Write the Nernst-Plank equation for mass transport in a generic electrolyte 12. Write the total current density equation in a generic electrolyte 13. Write Faraday’s law for electrolyte and reactants 14. Depict the polarization curve of a PEMFC with reasonable values 15. Depict the polarization curve of a PEM electrolyzer with reasonable values 16. Describe how the triple phase boundary is achieved in a catalyst layer of a PEMFC 17. List the more common materials adopted in the components of a MEA for PEMFC 18. List the more common materials adopted in the components of a MEA for PEM electrolyzer 19. Write the electrochemical reactions occurring in a PEMFC and the typical operating voltage range 20. Write the electrochemical reactions occurring in an alkaline electrolyzer and the typical operating voltage range 21. Write an example of electrochemical reactions occurring in a Lithium-ion battery and the typical operating voltage range 22. Depict the…