I'm trying to verify my GC measurement related to CO2 reduction in 0.5 M KHCO3, CO2 sat. I'm using Pt mesh as WE, which should give 100% FE of H2. I did this test to build a benchmark for my flow cell. But the FE H2 were higher than 100% (95% to 150%). i.e. The theoretical value of number of moles of H2 produced under 2C was 1.036E-05 mol but I got an experimental value of
1.14E-05 mol (110%). So I'm wondering if anyone happen to have the same issue before.
For GC detector, I use PDHID.
This happens mostly because of the following two reasons:
1) The flow rate is not consistent at the outlet. So you may receive a outburst of output flow which won't correspond to your current density.
2) Calibration of your GC with respect to your calibration gases is not proper. Please make sure that the calibration is done through the same cell configuration and all other parameters kept same.
