Enhanced ORR performance with biomass-derived freestanding catalyst layers: advancing mass transport in gas diffusion electrodes

Abstract

Proton Exchange Membrane Fuel Cells (PEMFCs) are increasingly recognized as a pivotal technology for transitioning the energy sector towards net-zero emissions. The efficiency of PEMFCs largely hinges on the development of catalysts, especially for the Oxygen Reduction Reaction (ORR) at the cathode. Currently, commercial PEMFCs predominantly utilize Pt-based catalysts for their exceptional activity and stability, highlighting the need for high catalytic efficiency to mitigate Pt scarcity issues. However, beyond intrinsic activity enhancements in catalyst development, the architecture of the catalyst layer—typically carbon-based—emerges as a critical, yet underexplored, factor. Here, we introduce a novel catalyst layer derived from lignin, a plentiful biomass resource in woody materials, crafted through a dual templating strategy to yield an interconnected hierarchical structure. Our evaluation of this unique catalyst layer within a gas diffusion electrode setup revealed significant improvements in mass transport. These advancements offer a sustainable and effective pathway for next-generation catalyst layer innovations in PEMFCs, potentially accelerating the widespread commercialization of this green technology to decarbonize the energy sector.