Exploring a Facile Synthetic Procedure of Iron-Based Platinum Group Metal-Free Electrocatalyst for Polymer Electrolyte Fuel Cells

The transportation sector, mainly powered by fossil fuels, is responsible for approximately 14% of all greenhouse gas emissions 1 . Polymer electrolyte fuel cells (PEFCs) are promising candidates for sustainable transport as they only emit water, can be refilled fast, and enable long ranges with a single refill. Their current costs and dependence on scarce materials challenge their broad implementation in heavy-duty vehicles and maritime transportation 2 . Another challenge is the catalyst degradation during operation, therefore the goal of at least 35,000 lifetime hours for heavy-duty transportation is ambitious as existing fuel cell vehicles have been engineered for ca. 5,000 hours 3 . The state-of-the-art catalyst layers are based on platinum nanoparticles supported on carbon and global efforts have been made to develop high-activity catalysts with reduced platinum contents, including platinum alloys such as Pt-Ni 4 and Pt-Co 5 , alternative supports such as nanotubes 6 , or a combination aforementioned methods. While platinum-based materials remain the most active for the oxygen reduction reaction, their elevated cost and instability during operation motivate the exploration of alternative materials. Platinum group metal (PGM)-free catalysts have gained prominence in the PEFCs field, where Fe-N-C based catalysts have shown high oxygen reduction reaction activity in acidic media 7 , approaching that of platinum-based catalyst layers, yet their practical application is hindered by insufficient stability under operating conditions 8 . Inspired by recent efforts 7,8 , our goal is to develop stable, active, and low-cost catalyst layers using earth-abundant materials. In this poster presentation, I will discuss my efforts in the synthesis of Fe-N-C catalysts by the incorporation of iron in a calcinated nitrogen-doped zeolitic imidazolate framework (ZIF). ZIFs are excellent supports due to their high porosity of approximately 60% and a surface area of 1600 m 2 /g, leading to a high density of active sites 9 . After the incorporation of iron, post-treatments are applied including leaching and the utilization of secondary nitrogen precursors, where efforts are made to develop non-hazardous activation approaches. The incorporation of secondary nitrogen precursors such as cyanamide have been shown to promote the formation of metal-N-C bonds and increase the performance towards the oxygen reduction reaction 10,11 . We employ microscopic, spectroscopic and electroc