Electrodes

Mebius is introducing our group of Gas Diffusion Electrode products which are loaded with our proprietary catalyst that is deposited via ink-jetting on the electrode surface as an extremely thin and even layer. The deposition technology allows us to prepare GDEs with very low Pt loadings (<0.01 mg/cm2 Pt) on any type of GDL in use for PEM fuel cells.

A cross-section view shows the Gas-Diffusion Layer (GDL) made from woven carbon fibers and a deposited layer of PtCu3/C catalyst that is approx. 60 µm thick. The smooth surface of the deposited catalyst is particularly note-worthy and is a consequence of the use of ink-jet material deposition technology on a carbon cloth surface. (Image is property of Mebius and the National Institute of Chemistry in Ljubljana.)

A magnified view of the catalyst layer cross-section that displays a porous structure, with pores of up to 200 nm in diameter. These pores act in place of the usually used additional microporous layer (MPL). Visible are the catalyst nanoparticles (brighter particles 20-30 nm in size), as well as PTFE and Nafion fibers, which form the three-phase contact zone, without which the electrode cannot function. (Image is property of Mebius and the National Institute of Chemistry in Ljubljana.)

Under even greater magnification we can see catalyst nanoparticles on carbon support. The size distribution of particles is relatively broad and contains particles from 2 nm up to 50 nm in size, with an average particle size of approx. 20 nm. Although the catalyst nanoparticles appear spherical, they are in fact polyhedra with a large number of crystalline facets (larger particles have over 100 crystalline facets!). (Image is property of Mebius and the National Institute of Chemistry in Ljubljana.)