Characterisation of a electrochemical hydrogen pump using electrochemical impedance spectroscopy

Electrochemical hydrogen pumps are electrochemical devices which are used for hydrogen purification and pressurization purposes. In such cells, gaseous hydrogen is oxidized at the anode and released at the cathode. Results presented in this paper are related to the characterization and optimization of a proton-exchange membrane (PEM) hydrogen pump using electrochemical impedance spectroscopy (EIS). Only the case of hydrogen purification is considered here. Current–voltage characteristics have been measured. The kinetics and efficiency of the cell have been investigated using EIS. The roles played by the cell structure (in particular by the ion-exchange polymer content in the electro-catalytic layers) and by different operating parameters (the cell temperature, the relative humidity and the partial pressure of hydrogen) on the overall process efficiency have been evaluated and are discussed.