11a Sustainable Recovery of Fuel Cell and Electrolyzer Materials

Renewable energy sources are experiencing a surge of growth due to rising power demand but suffer asynchronous production relative to societal needs. To balance the overproduction during low demand and underproduction during high demand, proton exchange membrane (PEM) based electrolyzers (capable of producing zero-carbon, green hydrogen) and fuel cells (for clean electricity generation and zero emission transportation) are utilized. Fully embracing this technology will require lowering the cost of these devices, currently hindered by expensive commercial PEM materials and platinum group metal (PGM) catalysts. Recycling efforts can lower the cost, but current means rely on incineration to recover the PGMs, producing hazardous byproducts and destroy the valuable PEM. More efficient and environmentally benign processes are necessary. Renewable energy sources are experiencing a surge of growth due to rising power demand but suffer asynchronous production relative to societal needs. To balance the overproduction during low demand and underproduction during high demand, proton exchange membrane (PEM) based electrolyzers (capable of producing zero-carbon, green hydrogen) and fuel cells (for clean electricity generation and zero emission transportation) are utilized. Fully embracing this technology will require lowering the cost of these devices, currently hindered by expensive commercial PEM materials and platinum group metal (PGM) catalysts. Recycling efforts can lower the cost, but current means rely on incineration to recover the PGMs, producing hazardous byproducts and destroy the valuable PEM. More efficient and environmentally benign processes are necessary. Specific approaches which will be assessed during Phase I are (i) minimal-solvent, low waste extraction, (ii) azeotropic mixture rinses designed to extract maximum amounts of PEM which can be easily recovered themselves and (iii) agitation/hot soaking techniques in non-hazardous solutions. In all cases the PGM catalyst recovery will be enhanced by capturing larger particles rather than recovering nanoparticles from soot by smelting or corrosive acids. Beneficial outcomes include: (i) a profound reduction in energy costs and expense of clean hydrogen; (ii) increased domestic PGM metal supply security, and (iii) a reduction of persistent fluorinated waste entering the environment from incineration of PEM or by their disposal into landfills from the perfluorosulfonic acid (PFSA) components of PEMs.