I'm a fresh man in the field of PEM electrolyzer. Recently, i made some PEM assembly for water electrolysis, but it always show low performance that is much lower than that of reported data (0.1 A cm-2 at 1.8 V). Besides, when it screwed tightly, it happens short-current...

All the process were conducted according to the literature report:

1. before assembly, the nafion117 was consequently boiled in 3% H2O2, 0.5 M H2SO4, and DI water, respectively.

2. the Pt/C, IrO2 was fully dispersed in i-PrOH, H2O and nafion (loading IrO2:2 mg cm-2, Pt: 1 mg cm-2, nafion: 20% of catalyst), which is sprayed on PTFE film and decal transfer onto nafion membrane via hot-press under 135 ℃, 40 kg (perfect transfer).

3. Freudenberg carbon papers were used as GDL for both anode and cathode, which is treated with piranha solution before use for increasing hydrophilicity.

4. The GDL and MEA was hot-pressed under 80 ℃, 40 kg. Then, it assembled in PEM electrolyzer and measure the i-E curves with 80 ℃ flow DI water.

That is my all procedure, can anyone tell me what should i improve more?

Thanks for all.