Have proton exchange membrane fuel cells been designed for recycling?

Considering the widespread use of proton exchange membrane (PEM) fuel cells, end-of-life management is critical. The main component of PEM fuel cells is the membrane electrode assembly (MEA), comprising a Nafion membrane sandwiched between two electrodes. The electrodes are made of platinum supported on carbon (Pt/C) and held together by the Nafion binder. Researchers have mainly focused on the recovery of platinum from the MEA. The low concentration of platinum in the electrodes makes thermal decomposition of the fluorinated polymeric binder, followed by a hydrometallurgy step being the most practical way to liberate and concentrate the platinum catalyst. In this manuscript, we show the use of aqueous ethanol and isopropyl alcohol to swell the PEM and recover it intact. The solvent mixture containing the electrodes is then subjected to microwave heating to dissolve the Nafion binder and liberate the Pt/C which can be further enhanced with induced mixing. This approach offers the potential for MEA short loop recycling. The proposed approach concentrates 87% of the platinum catalyst while being able to produce clean Nafion membrane. Finally, we show that the recycled gas diffusion layer can be re-used to create a new MEA with a slight decrease in performance.