Faradaic efficiency: measuring and improving it
Faradaic efficiency (FE) is the percentage of electrons that effectively form the desired product (H₂, Cl₂, etc.) versus the total applied charge. A 95% FE means 5% of the energy is lost to side reactions.
How to measure it
Measuring FE requires quantifying the product generated (dry gas volume at known P and T, or chromatographic analysis) and comparing it to the theoretical Faraday charge. In the lab this is done with a three-electrode cell and bubble meter; in industrial settings with a calibrated mass flow meter.
How to improve it
- Catalyst selectivity (avoid HER on AWE anodes).
- Effective gas separation to avoid crossover.
- Operation at optimal current density (not too low).
For our AWE electrodes we guarantee FE > 99% under nominal operating conditions.