Facilitating ion and bubble transports on a patterned proton exchange membrane in water electrolyzer

Abstract

Proton exchange membrane (PEM) water electrolysis is emerging as a promising technology for the mass production of green hydrogen, which is essential for the transition to a sustainable energy system. In this paper, we demonstrate enhanced performance of a PEM electrolyzer with patterned PEM in membrane electrode assembly (MEA). Using a transparent visualization cell, we directly observe bubble generations caused by redox reactions occurring at the interphase of the catalyst and electrode layers in a PEM electrolyzer. The presence of the pattern on PEM reduces the size of the bubbles, which leads to improved ion and bubble transfers, which directly correlates to improved performance. Also, the redox reactions are more evenly distributed compared to the non- patterned pristine PEM. Such improvements with the patterned PEM are also identified by electrochemical responses in linear voltage sweep, chronoamperometry, and electrochemical impedance spectroscopy. To the best of our knowledge, this is first demonstration of water electrolysis with the patterned PEM. With considerable reduction of cell resistance and enhanced mass transfer, the patterned PEM offers new possibilities for engineering-better PEM electrolyzer.