ABSTRACT Reliable and reproducible membrane electrode assembly (MEA) benchmarking is critical for meaningful evaluation of proton exchange membrane fuel cell (PEMFC) performance, yet laboratory‐scale MEA fabrication and testing remain highly sensitive to experimental variables that are often insufficiently detailed in literature reports. Here, we present transparent methodologies for trustworthy MEA benchmarking and systematically assess how key MEA fabrication and testing parameters influence PEMFC performance. We demonstrate consistent fabrication of catalyst‐coated membranes implemented in an automated direct ink‐spraying setup and establish calibrated X‐ray fluorescence analysis for accurate determination of actual catalyst loadings. Different gas diffusion media and cathode catalysts strongly affected mass transport and O 2 reduction kinetics, respectively, whereas the effects of anode catalysts were minor. Incorporating molecular additives such as cyclohexanol and β‐cyclodextrin in a Pt 3 Co intermetallic cathode layer markedly improved O 2 mass transport without compromising O 2 reduction kinetics, yet device durability was not enhanced by these additives even with the presence of a CeO 2 radical scavenger. Hot‐pressing did not necessarily improve device performance and could induce unintended losses, and polarization curve scan direction appreciably influenced the extracted kinetic metrics of Pt‐based catalysts. This work provides practical guidelines for standardized, reproducible, and comparable evaluations of electrocatalysts and functional additives in PEMFCs.
Yu et al. (Fri,) studied this question.