Electrocatalysts for fuel cells synthesized in supercritical carbon dioxide

We applied the method of directly depositing an organometallic precursor from a solution in supercritical carbon dioxide on a dispersed carbon substrate surface followed by reduction to obtain a number of electrocatalytic materials in the form of nanoscale platinum particles on dispersed carbon supports (Vulcan XC72r carbon black, acetylene black, nanotubes). The synthesized materials persistently showed a monodisperse size distribution of platinum particles with an average diameter of 2–3 nm, regardless of the substrate nature, and a uniform distribution over the support surface. The synthesized electrocatalysts (ECs) were tested as part of an operating cathode electrode of a phosphoric acid fuel cell (FC) with a PBI matrix. In this case, the membrane-electrode assembly with this cathode showed current-voltage characteristics as good as the reference characteristics achieved with electrodes produced by BASF.