Anion exchange membrane electrochemical hydrogen compression: Performance, catalyst influence, and impedance analysis

Electrochemical hydrogen compression offers compact, low noise hydrogen compression without moving parts and has the potential to combine hydrogen compression and purification. While most electrochemical compressors rely on proton exchange membranes with platinum group metal catalysts and fluorinated materials, anion exchange membrane systems could enable fluorine free membranes and broader catalyst choices. An alkaline anion exchange membrane based single cell electrochemical hydrogen compressor was developed and experimentally evaluated. With Pt/C electrodes, current densities of up to 75 mA cm −2 at 0.82 V were achieved. Potentiostatic operation demonstrated electrochemical hydrogen compression to 11.6 bar absolute pressure. In this pressure range, the first stage of conventional mechanical compressors typically operates at comparatively low efficiency, which makes this research highly relevant. Replacing the cathodic Pt/C electrode with Raney nickel still enabled 48 mA cm −2 at 0.58 V. Impedance spectroscopy identified key bottlenecks for performance improvement. The results provide an early experimental demonstration of alkaline AEM electrochemical hydrogen compression.