TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The metal in the complex comprises manganese, cerium, platinum, platinum supported on carbon (all preferred), cobalt, iron, copper, palladium, platinum-cobalt, or their ions. The (ligand) is bathophenanthroline, 1,10-phenanthroline-5-amino, or terpyridine. The molar ratio of metal to ligand in the complex is 1:1-1:5. The amount of the metal-ligand complex additive in the composite polymer electrolyte is greater than 0.5% (preferably 0.5-1%) by weight of the proton conducting ionomer. The precursor for the metal is cerium(III) nitrate hexahydrate, manganese(IV) oxide, tetraammineplatinum(II) nitrate, platinum/carbon, platinum(IV) chloride, manganese(II) acetate tetrahydrate, (all preferred), palladium, platinum, manganese, cobalt, rhodium, copper, osmium, nickel, iridium, silver, titanium, cerium, ruthenium, chromium, zirconium, iron, cerium(IV) oxide, ruthenium(IV) oxide, tungsten(VI) oxide, cerium(III) phosphate, chromium(III) phosphate, aluminum phosphate, cerium trifluoride, silicon dioxide, cerium(IV) sulfate, manganese(III) oxide, manganese(II) oxide, manganese sulfate, manganese(II) chloride, manganese(II) nitrate, cobalt(II) chloride, cobalt(II) nitrate, cobalt(II) bromide, cobalt(II) phosphate, cobalt(II) acetate, cobalt(II) sulfate, cobalt(II) dihydrogen phosphate, nickel(II) fluoride, nickel(II) sulfate, nickel(II) bromide, nickel(II) chloride, nickel(II) phosphate, nickel(II) acetate, nickel(III) hydroxide, nickel(III) oxide, nickel(II) oxide, iron(II,III) oxide, iron(III) oxide, iron(II) chloride, iron(III) chloride, cerium(III) nitrate, zinc peroxide, zinc chloride, zinc nitrate, titanium(II) fluoride, titanium(IV) fluoride, copper(I) chloride, copper(II) chloride, copper(II) sulfate, copper-nickel alloy, platinum-cobalt alloy, platinum-gold alloy, or ruthenium(IV) oxide-aluminum oxide.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The proton conducting ionomer is perfluorosulfonic acid ionomer or hydrocarbon ionomer. In the membrane electrode assembly, the membrane electrolyte or the cathode catalyst layer comprises the composite polymer electrolyte. Preferred Definitions:    R1, R2 = amino or phenyl.    EXAMPLE - In a vial, bathophenanthroline (0.0207 g, 1 wt.% of perfluorosulfonic acid (PFSA)), cerium(III) nitrate hexahydrate (0.0065 g, where molar ratio of bathophenanthroline to cerium ion (Ce3+) was 4:1) and PFSA ionomer dispersion (9.32 g, solids concentration 22%) were stirred overnight at 50 degrees C. A cerium-bathophenanthroline additive (C1) was formed in solution and a membrane sample comprising 1% of the C1 additive was cast from the solution to give the proton conducting composite polymer electrolyte.