Fig. 5: PEMEW test.

a, b Photograph (a) and the corresponding schematic structure (b) of PEMEW device. c Polarization curves of the PEMWE no iR-correction. d Durability test of the single-cell PEMWE measured with a current density of 1 A cm−2 in 0.5 M H2SO4 aqueous solution at 80 °C. The blue arrows in (b) indicate the transfer direction of molecules.