In the past few decades, many improvements have been achieved regarding the PEMFCs components, the cell/stacks design as well as the architecture of the overall system. Hence, the level of maturity of PEMFC systems recently became sufficient to enable their commercialization for automotive applications (FCEV Miraï by Toyota, FCEV Nexo by Hyundai, etc.). However, despite great initial performance, PEMFC systems still suffer technological limitations, such as their initial cost and overall durability in real life operation, which prevents widespread industrial deployment. Some of these limitations can be overcome by combining experiments and modelling to characterize and better understand the behaviour of the carbon-supported platinum (Pt/C) electrocatalyst, its utilization/effectiveness in PEMFC catalyst layers and to be able to predict the performance and durability of PEMFC. This should help making the most relevant choices to accelerate the development processes of PEMFC.In this work, physico-chemical and electrochemical measurements are performed from the scale of the raw Pt/C materials up to the complete catalyst layer, to gather as much information as possible on the catalytic layer micro-structure and its operating properties. Coupling experiments in classic RDE and in PEMFC differential-single cell (1.8 cm² under high reactant stoichiometry) enables to fully characterize the electrochemical properties and behaviour of our materials. These different measurements are performed under various ideal and well-controlled operating conditions: cell temperature (T), relative humidity (RH), partial pressure of O2 (PO2 ) were chosen to be relevant and to dissociate and characterize as much as possible the different electro-chemical mechanisms involved in the catalyst layers of PEMFC. In parallel; several models have been developed to simulate one or combined mechanisms leading to the performance [1] and degradation of cell components[2], [3]. In fact, models aim at isolating and quantifying the contribution of each mechanism by choosing relevant operating conditions. Based on our experimental work and data sets, the behaviour of the Pt/C electrocatalysts has been studied in order to introduce new electrocatalytic features and especially the Pt surface oxide formation and reduction which is linked to Pt surface state. This preliminary step was then further developed into, a complete performance model for the O2 reduction reaction at the cathode to better describe the physical and electrochemical phenomenon involved in 0D and 1D catalyst layers during fuel cell operation. In this new description, the position of the main adsorption/desorption peaks are well captured by the simulation compared to experiment keeping complete physical meaning.This work has partially received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking under grant agreement No. 875025 (FURTHER-FC project). This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation programme, Hydrogen Europe and Hydrogen Europe Research.[1] B. Randrianarizafy, P. Schott, M. Chandesris, M. Gerard, and Y. Bultel, “Design optimization of rib/channel patterns in a PEMFC through performance heterogeneities modelling,” International Journal of Hydrogen Energy, vol. 43, no. 18, pp. 8907–8926, May 2018, doi: 10.1016/j.ijhydene.2018.03.036.[2] T. Jahnke, G. A. Futter, A. Baricci, C. Rabissi, and A. Casalegno, “Physical Modeling of Catalyst Degradation in Low Temperature Fuel Cells: Platinum Oxidation, Dissolution, Particle Growth and Platinum Band Formation,” J. Electrochem. Soc., vol. 167, no. 1, p. 013523, Nov. 2019, doi: 10.1149/2.0232001JES.[3] G. Maranzana, A. Lamibrac, J. Dillet, S. Abbou, S. Didierjean, and O. Lottin, “Startup (and Shutdown) Model for Polymer Electrolyte Membrane Fuel Cells,” J. Electrochem. Soc., vol. 162, no. 7, pp. F694–F706, 2015, doi: 10.1149/2.0451507jes. Figure 1
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Jul 21, 2024
S K Das + 1
Open Access
