TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The transition metal is platinum, palladium, cobalt, nickel, chromium, molybdenum, iron, manganese, vanadium, and/or tungsten.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The organic solvent is xylene, 1,2-dichlorobenzene, toluene, or mesitylene.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The recast ionomer is poly(perfluorosulfonic acid) (preferred), sulfonated styrene-ethylene-butylene-styrene, polystyrene-graft-poly(styrene sulfonic acid), poly(vinylidene fluoride)-graft-poly(styrene sulfonic acid), poly(arylene ether), polyphosphazene, and/or their derivatives. EXAMPLE - As-received ruthenium (Ru) black (99.9%) was reduced at 230 plus minus 10 degrees C for 1 hour under hydrogen (ultra high purity (UHP)) flow and then cooled down to room temperature in hydrogen, which was then replaced with argon (UHP). A suspension of selenium (Se) powder in xylene was prepared using Se powder ( approximately 200 mesh, as-received) and xylene, which was dried using molecular sieves (4A) for one week prior to use. The suspension was pre-purged with argon for 30 minutes and then injected into a flask containing the reduced Ru black. The mixture was heated up to the solvent boiling point ( approximately 140 degrees C) and kept under reflux for 24 hours while maintaining a slow flow of argon through the suspension. After the reaction took place, the solid particles were separated from the solvent by centrifugation, and then washed with anhydrous ethyl ether six times before being finally dried under vacuum for 2 hours. As-received Ru black revealed the presence of Ru oxides and a small amount of metallic Ru. Elemental Ru was recovered by reducing the oxidized sample in hydrogen. The X-ray diffraction pattern (XRD) indicated that the Ru particle size was on the order of 11.6 nm. The XRD pattern obtained after refluxing the Ru powder with Se in xylene indicated that the particle size of the Ru/Se material was 30% less than that of the initial reduced elemental Ru precursor without Ru material loss, indicating that Se had interacted with the Ru powder to reduce the particle size of the powder.