While not everyone considers the intricacy of the Proton Exchange Membrane Fuel Cell (PEMFC) that powers our FC vehicles, teams of people at R&D cannot stop thinking about them. They dream of electrical connections, thermal management, how to fit the package in the vehicle, and fundamental electrochemistry. One team dreams of the required catalyst which converts the hydrogen fuel into water and electrons for electricity that makes the whole thing work. This oxygen reduction catalyst is generally platinum nanoparticles in a matrix of electron conductive carbon surrounded by proton conductive polymer, but there is hope for new materials with desirable properties.
Toyota Research Institute of North America’s Materials Research Department details their effort to improve activity and durability the oxygen reduction catalyst in their publication “Dimeric ionic liquid for improving performance and durability of PEMFCs” found in the Journal of Power sources. While methods such as Pt-alloy core/Pt shell structures, alloying of with other metals and nitriding have been investigated and widely reported, this work investigates a surface modification technique that is much simpler and cost effective than such methods. Whereas previous investigation showed the benefit of incorporating an ionic liquid component, the effect diminished over time as the water produced by the H2+O2 reaction dissolved the incorporated ionic liquid. The developed high melting point, dimeric ionic liquid is more stable than other ionic liquids, and the dimeric ionic liquid modified catalyst showed significant improved activity and durability. This work is the first publication from Toyota with current 2nd gen Mirai MEA materials and shows significantly better performance than published data in FC community. It is hoped that this work will spur the fuel cell community to consider out of the box approaches for future FC development.
Learn More: https://doi.org/10.1016/j.jpowsour.2022.232488
