The objective of this project is to quantify the limitations to proton and oxygen transport in proton exchange membrane fuel cell (PEMFC) electrodes, by analyzing the results of electrochemical measurements by limiting current and electrochemical impedance spectroscopy (EIS) thanks to 1D and/or 2D models under COMSOL and MATLAB. On the one hand, there is the experimental side of the project of setting up, validating, and exploiting electrochemical characterization methods that will allow dissociating and quantifying the transport limitations, mainly focusing on the protons and diffusion of oxygen. In PEMFC electrodes the study of the polarization curve, limiting current effect under oxygen and hydrogen is done.