Catalyst Layer Optimization in Proton Exchange Membrane Fuel Cells

The catalyst layer within a proton exchange membrane fuel cell (PEMFC) is central to its electrochemical performance, durability and cost. This layer comprises platinum or non-precious metal nanoparticles supported on carbon, dispersed within an ionomer binder and coated onto a gas diffusion layer. Optimization focuses on achieving a homogenous distribution of catalyst and ionomer, maximising active surface area while maintaining continuous pathways for proton, electron and gas transport. Control over catalyst ink composition—ratio of catalyst to ionomer, solvent choice and solid content—governs microscale structure formation. Hierarchical pore architectures are engineered to minimise mass transport resistances and facilitate water management, thereby enhancing power density and durability. Advanced manufacturing methods including ultrasonic spray, gravure and roll-to-roll coating enable scalable, uniform films with controlled thickness and porosity. Recent advances leverage multiscale characterisation and modelling to link ink formulation, drying dynamics and catalyst layer morphology, guiding rational design of next-generation PEMFC catalyst layers with reduced precious metal loadings and improved lifetime.

Research from Nature Portfolio

Recent studies have elucidated the role of dispersion solvent composition on ionomer aggregation and distribution within catalyst inks. By combining dynamic light scattering and molecular-dynamics simulation, researchers demonstrated that mixed dipropylene glycol/water solvents modulate ionomer solvation energy and backbone conformation. Higher water content increases ionomer aggregation, reducing uniform dispersion and potentially compromising proton conduction networks. These insights inform the selection of solvent mixtures that promote optimal ionomer film formation and catalyst layer homogeneity.

Catalyst Layer Optimization in Proton Exchange Membrane Fuel Cells publication trend

The graph below shows the total number of articles in catalyst layer optimization in proton exchange membrane fuel cells across all publications each year (not limited to Nature Index journals).

Technical terms

Catalyst layer: Thin film containing catalyst particles and ionomer that facilitates electrochemical reactions in a fuel cell.

Ionomer: Proton-conductive polymer binder that provides ionic pathways between catalyst particles and the membrane.

Catalyst ink: Suspension of catalyst nanoparticles, ionomer and solvent used to coat the gas diffusion layer.

Membrane electrode assembly (MEA): Integrated unit of membrane, catalyst layers and gas diffusion layers in a PEMFC.

Gas diffusion layer (GDL): Porous substrate that supports catalyst layers and ensures uniform gas distribution and water removal.

Solvation energy: Energy change associated with ionomer dissolution or dispersion in a given solvent, influencing aggregation behaviour.

Mass transport: Movement of reactants and products (protons, electrons, gases, water) through catalyst layer pores and ionomer networks.

References

1. Recent Advances on PEM Fuel Cells: From Key Materials to Membrane Electrode Assembly. Electrochemical Energy Reviews (2023).
2. Effect of Catalyst Ink and Formation Process on the Multiscale Structure of Catalyst Layers in PEM Fuel Cells. Applied Sciences (2022).
3. Gravure Coating for Roll-to-Roll Manufacturing of Proton-Exchange-Membrane Fuel Cell Catalyst Layers. Journal of The Electrochemical Society (2018).
4. Dispersion-Solvent Control of Ionomer Aggregation in a Polymer Electrolyte Membrane Fuel Cell. Scientific Reports (2018).
5. Recent progress in understanding the dispersion stability of catalyst ink for proton exchange membrane fuel cell and water electrolyzer. International Journal of Hydrogen Energy (2024).
6. Hydrocarbon Ionomeric Binders for Fuel Cells and Electrolyzers. Advanced Science (2023).
7. Correlating catalyst ink design and catalyst layer fabrication with electrochemical CO2 reduction performance. Chemical Engineering Journal (2023).