TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The composition further comprises: a base metal compound comprising base metal hydroxides, base metal oxides and/or base metal carbonates; cerium ions in an amount that neutralizes up to 5% of the acidic groups in the ionomer; and a reducing agent. The composition is clear. Preferred Components: The precious metal precursor compound has a low water solubility of 0.0001-0.1 mole/l (as determined at 22 degrees C). The precious metal of the precursor compound is: platinum, palladium, iridium (all preferred), rhodium, ruthenium, gold and/or silver; a precious metal hydroxide, a precious metal hydroxo complex and/or a hydrated oxide of a precious metal; of formulae (Ag2OnH2O), (PtO2nH2O), (PdOnH2O), (Ir2O3nH2O), (IrO2nH2O), (Ru2O3nH2O), (H2Ir(OH)6) or (Rh2O3nH2O), silver hydroxide, gold(III) hydroxide, hydrogen hexahydroxoplatinate, palladium hydroxide, iridium hydroxide, iridium(IV)hydroxide, ruthenium hydroxide and/or rhodium hydroxide; and dihydrogen-hexahydroxo(IV)platinate (H2Pt(OH)6), iridium(IV) hydroxide (Ir(OH)4) or palladium(II) hydroxide (Pd(OH)2). The base metal compound is: cobalt(II) hydroxide, nickel(II) hydroxide, copper(II) hydroxide, manganese(II) hydroxide, chromium(III) hydroxide, cobalt oxide, nickel(II) oxide, copper(I) oxide, copper(II) oxide, manganese(IV) oxide, manganese dioxide, chromium(III) oxide, cobalt(II) carbonate, nickel(II) carbonate, copper(II) carbonate, manganese(II) carbonate and/or chromium III carbonate; and base metal hydroxides, base metal oxides and/or base metal carbonates. The nano-sized precious metal particles have an average particle size of 0.5-100 nm, preferably 2-20 nm (as detected by transmission electron microscopy). The colloidal dispersion further comprises electrically conductive and/or electrically non-conductive support materials. The electrically conductive support material is: carbon black powders, graphitized carbon blacks, carbon nanotubes, carbon nanohorns, graphenes, carbon platelets, carbon fibers, electrically conductive ceramic powders, ceramic nanotubes and/or electroconductive polymer materials; and a supported platinum or platinum alloy catalyst. The electrically non-conductive support material is alumina, silica, titania, ceria, zirconia, calcium carbonate and/or barium sulfate. The colloidal dispersion is essentially free from additional components such as surfactants, inorganic salts, halide ions, mineral acids or other anionic or cationic species.n = 0.1-10.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The reducing agent is: an aliphatic alcohol comprising methanol, ethanol, 1-propanol, isopropanol and/or 1-butanol; and hydrogen, hydrazine, formaldehyde, formic acid and/or oxalic acid. Preferred Method: The reduction process is carried out for a time period of 1-120 hours at temperatures of 5-40 degrees C, preferably 20-25 degrees C. The steps (a) and (b) are: conducted separately; and conducted simultaneously within a time period of 1-120 hours, preferably 1-48 hours. The method further comprises adding the electrically conductive and/or electrically non-conductive support material.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The acidic ionomer is an acidic perfluorinated ionomer compound. The acidic ionomer compound comprises acidic groups comprising sulfonic acid groups (-SO3H), carboxylic acid groups (-COOH), phosphonic acid groups (-PO3H2), bis-sulfonyl imide groups of formula (Rf1-SO2-NH-SO2-R1af2), bis-carbonyl imide groups of formula (Rf1-CO-NH-CO-R1af2) and/or sulfonyl-carbonyl imide groups of formula (Rf1-SO2-NH-CO-R1af2).Rf1, R1af2 = fluorine-containing carbon chains. EXAMPLE - 100 g of Ionomer dispersion (comprising 20 wt.% of solid ionomer and 80 wt.% of deionized water) was charged into a 300 ml vessel. 375 g of Milling media was added to the dispersion. 1.06 g of Dihydrogen hexahydroxy(IV)-platinate was added to the vessel and milled for 2 hours to obtain a liquid composition.