Observation of the Electrochemically active Surface Area in a Proton Exchange Membrane Fuel Cell

In this paper a methodology for the estimation of the Electrochemically active Surface Area (ECSA) of a Proton Exchange Membrane Fuel Cell (PEMFC) is developed. Specifically, the ECSA in the Cathode Catalyst Layer (CCL) is estimated, which makes it possible to quantify the amount of active platinum (Pt) in the CCL. In order to estimate the ECSA, the internal conditions of the PEMFC have to be known. A model-based observer for the distributed parameter dynamics is designed. From the observation of the distributed states, the ECSA can be estimated as well. With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a two-phase water model and the effects of liquid water on the CCL. The results of the methodology are discussed in a simulation environment using the New European Driving Cycle (NEDC) as a case study.