Environmentally Friendly Recycling of Fuel-Cell Membrane Electrode Assemblies by Using Ionic Liquids

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Science

Background:

• Platinum nanoparticles are key catalysts in proton exchange membrane fuel cells (PEMFCs), but their high cost (~46% of total cell price) hinders commercialization.
• Current platinum recovery methods, such as pyro-hydrometallurgical processes, involve harsh conditions and generate harmful emissions (fumes, NOx).

Purpose of the Study:

• To develop a cost-effective and environmentally friendly method for recycling platinum catalysts from spent PEMFCs.
• To investigate the electrochemical recovery of platinum using ionic liquids as a sustainable alternative.

Main Methods:

• Electrochemical leaching of platinum from fuel cell electrodes using chloride-based ionic liquids (ILs).
• Electrodeposition of leached platinum.
• Study of platinum leaching in pure ILs and IL melts at varying temperatures and chloride concentrations.
• Development of a single-cell process for platinum recovery under inert or ambient atmosphere.

Main Results:

• The proposed electrochemical route operates under mild temperature conditions and produces no gas emissions.
• Platinum leaching and electrodeposition were successfully achieved by modulating the composition of ionic-liquid melts.
• The process allows for the recovery of platinum from fuel cell electrodes within a single-cell setup.

Conclusions:

• Electrochemical recovery of platinum from PEMFCs using ionic liquids is a viable and sustainable alternative to conventional methods.
• This approach significantly reduces production costs and environmental impact associated with platinum catalyst recycling.