PNNL

Abstract

Hydrogen production using proton exchange membrane water electrolysis (PEMWE) cells has been paid much attention because of their high efficiency and no harmful emissions. In PEMWE cells, porous transport anodes (PTAs) made up of catalyst layer (CL) with oxygen evolution reaction (OER) catalysts, porous transport layer (PTL), and PEM play key roles in stack performance and lifetime. Ir-based and non-precious metal OER catalysts highly active and stable at low pH and high anodic potentials have been studied through understanding of OER mechanisms. Various strategies engineering CLs and PTLs to improve interfacial properties and mass transfer of reactants and products to and from the active sites have been proposed. Additionally, diagnoses of PTAs are also significantly crucial to interpret electrochemical processes and to address their current challenges. Half-cell analyses that include diffusion electrode (DE), floating electrode (FE), and modified rotating disk electrode (MRDE) techniques have been explored and membrane electrode assembly (MEA)-based analyses such as polarization technique, electrochemical impedance spectroscopy, and magnetic field analysis have been established. This paper aims to provide an overview of recent technologies used for engineering and diagnosing tools of PEMWE cells, as well as insights into the advanced components and systems to be developed in this field.