Abstract
Hydrogen and oxygen crossover in polymer electrolyte membrane (PEM) electrolyzers is critical for both operational safety and product gas purity. In this study, we present a versatile experimental setup designed to quantify gas crossover through membranes and polymers commonly used in PEM electrolyzers. A key feature of the setup is its ability to perform in situ measurements on fully assembled PEM cells, containing complete membrane electrode assemblies (MEAs). The system also enables characterization of gas permeation through both wet and dry ionomers, as well as various polymers employed in components such as gaskets and tubing. These capabilities are demonstrated through a series of representative measurements that highlight the setup's flexibility and potential.