A twin-wire arc deposition method for depositing a nano-structured catalyst
coating onto a
solid electrolyte membrane or an
electrode substrate from a precursor catalyst material selected from the group consisting of a
metal,
metal alloy,
metal compound, and
ceramic material. The method includes the steps of (a) providing an ionized arc
nozzle comprising two consumable
electrode and a working gas flow to form an ionized arc between the two electrodes, wherein the consumable electrodes provide the precursor catalyst material vaporizable therefrom by the ionized arc; (b) operating the arc
nozzle to heat and at least partially vaporize the precursor catalyst material for providing a
stream of nanometer-sized vapor clusters of the precursor catalyst material into a chamber in which the membrane or the
electrode substrate has been placed; and (c) introducing a
stream of a carrier gas into the chamber to impinge upon the
stream of precursor vapor clusters to produce depositable
nano clusters which are carried by the carrier gas to deposit onto a first side of the membrane or the electrode substrate for forming the nano-structured catalyst
coating. Such a catalyst-
coated membrane or electrode can be incorporated as a part of a fuel
cell.