TECHNOLOGY FOCUS - METALLURGY - Preferred Component: The carrier gas comprises a reactive gas reacting with the precursor vapor clusters for producing the deposits of nano clusters that are metal compounds or ceramic materials. The precursor material comprises transition metal element(s) from Groups IB, IIB, IIIB, IVB, VIB, VIIB, or VIII elements of the Periodic Table of Elements. The Group IB includes copper, silver, and gold. The Group IIB includes zinc, cadmium, and mercury. The group IIIB includes scandium, yttrium, and lanthanum. The Group IVB includes titanium, zirconium, and hafnium. The Group VB includes vanadium, niobium, and tantalum. The Group VIB includes cobalt, molybdenum, and tungsten. The Group VIIB includes manganese and rhenium. The Group VIII includes iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, and platinum. The stream of reactive gas comprises gas from hydrogen, oxygen, carbon, nitrogen, chlorine, fluorine, boron, sulfur, phosphorus, selenium, tellurium, and/or arsenic vapor. The carrier gas comprises an inert gas.The substrate comprises a train of individual pieces of porous electrode substrate material or solid electrolyte membrane material being moved into the chamber and moved out of the chamber after forming the coating. The porous electrode substrate comprises a micro-porous metal or oxide structure that is electronically conducting. The solid electrolyte membrane substrate comprises a porous solid oxide structure. The precursor material comprises an alloy of at least two metallic elements. The stream of carrier gas contains a reactive gas that reacts with the precursor catalyst vapor clusters in a manner that the reaction heat released is used to sustain the reaction until most of the precursor vapor clusters are converted to nanometer-sized metal compound or ceramic clusters. The gas permeable porous substrate layer comprises carbon and/or oxide particles. The membrane is a proton exchange membrane.Preferred Method: At least a second ionized arc nozzle is operated to completely vaporize the precursor material. The stream of carrier gas is pre-heated prior to injection to impinge upon the precursor vapor clusters. The arc nozzle is operated by melting the precursor material and atomizing the material to form nanometer-scaled droplets of the material. The liquid droplets are mixed with the stream of vapor clusters.Preferred Property: The catalyst region has a thickness of 0.05-5 mum. The catalyst loading is 0.1-0.3 mg/cm2.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The solid electrolyte membrane substrate comprises an ion exchange polymer that is electronically conducting.