Comprehensive study and optimization of membrane electrode assembly structural composition in proton exchange membrane water electrolyzer

Hydrogen production from the proton exchange membrane (PEM) water electrolysis process provides a promising solution for renewable energy storage. As the site where the electrochemical reactions occur in the PEM electrolyzer, the structure and performance of membrane electrode assembly (MEA) significantly affect the cell efficiency and device fabrication cost. In this paper, porous transport layers (PTLs) and catalyst coating membranes (CCM) that constitute MEA are studied. The use of platinum-coated titanium felt in the anode significantly reduces the cell voltage and ohmic resistance compared with uncoated PTL, while titanium felt works better than carbon paper in the cathode. Higher catalyst loading can provide sufficient active sites for electrode reaction, and 11.1 wt% ionomers provide the best proton and gas transport channel. After optimization, the cell voltage is reduced to 1.840 V at 2 A/cm2, and the efficiency reaches 79%. This paper provides insights for developing efficient and economical PEM electrolyzers.