Vertically aligned carbon nanofibers promise more cost-efficient PEM water electrolyzers

PEMWE is rec­og­nized as a key tech­nol­o­gy for sus­tain­able hydro­gen pro­duc­tion. How­ev­er, the neces­si­ty of using plat­inum group met­als (PGMs) as cat­a­lysts sets up a bar­ri­er for estab­lish­ing GW-scale sys­tems. Espe­cial­ly on the anode side for oxy­gen evo­lu­tion, the load­ing of irid­i­um cat­a­lyst must be reduced sig­nif­i­cant­ly from cur­rent­ly 2 mgIr cm‑2 to 0.05 mgIr cm‑2 lev­el to enable large scale appli­ca­tion of PEMWE [1]. Even though sub­stan­tial progress has been made, there remain tremen­dous chal­lenges to make PEMWE work at ultra-low load­ings in practice. 

Ver­ti­cal­ly aligned car­bon nanofibers (CNF) cre­ate low-tor­tu­os­i­ty con­duct­ing 3D nanos­truc­tures over porous trans­port lay­ers (PTLs), act­ing as sup­ports for ultra-low load­ing of irid­i­um cat­a­lyst with non-com­pro­mised per­for­mance. Pro­ton exchange mem­brane water elec­trol­y­sis (PEMWE) is envis­aged to be more effi­cient using such advanced PTLs. 

Read more on: https://learn.mines.edu/wp-content/uploads/2022/06/ICE2021_ProgramComplete01.with-links.6.17.22.pdf (page 24–25).