TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The catalyst is platinum (Pt) or an alloy comprising platinum and at least one group of gold, palladium, rhodium, iridium, ruthenium, tin, molybdenum, cobalt or chromium. Preferred Components: (A) further comprises a binder. The content of the binder is present at 0.001-0.5 parts by weight, based on 1 part by weight of the catalyst.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The method further comprises adding a binder to the coating solution. Preferred Components: The content of group of the monomer (I) and/or (II), the homopolymer consisting of (I), the homopolymer consisting of (II), and the copolymer consisting of (I) and (II), is 0.01-0.5 parts by weight based on 1 part by weight of the catalyst. The binder is poly(vinylidenefluoride), polytetrafluoroethylene, a tetrafluoroethylenehexafluoroethylene copolymer or perfluoroethylene. SPECIFIC COMPOUNDS - The use of 17 compounds (I) is specifically claimed e.g. 6-tert-butyl-3-(2,4-difluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine, 6-tert-butyl-3-(3,4-difluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine, 6-tert-butyl-3-(2,4,6-trifluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine, 6-fluoro-3-(4-fluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine and 6-tert-butyl-3-(4-fluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine of formula (Ia). The use of tris(3-(2,4-difluoro-phenyl)-6-fluoro-3,4-dihydro-2H-benzo(e)(1,3)oxazin-6-yl)ethane, 2,2-bis(3-(2,4,6-trifluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazin-6-yl)propane, 2,2-bis(6-methyl-3-(3-trifluoromethyl-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine)propane, and 2,2-bis(3-(2,4-difluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazin-6-yl)propane of formula (IIa) is specifically claimed as (II).    EXAMPLE - A platinum cobalt carbon catalyst (PtCo(TEC36E52)) (1 g, 50 wt.% on carbon) and N-methylpyrrolidinone (NMP) (3 g) were introduced into a stirring vessel. The reaction mixture was stirred using a mortar to make slurries. A solution of 6,7-difluoro-3-(4-fluoro-phenyl)-3,4-dihydro-2H-benzo(e)(1,3)oxazine (A) (10 wt.%) in NMP was added to the slurries, to produce (A) (0.026 g) followed by stirring. Then, a solution of a vinylidenefluorideco-hexafluoropropylene copolymer (5 wt.%) in NMP was added to the mixture, to produce vinylidenefluoride-cohexafluoropropylene copolymer (0.026 g), followed by mixing for 10 minutes, to make slurries for cathode catalyst layers. Carbon papers were cut into 4x7 cm2 pieces and fixed on glass plates. The slurries for the cathode catalyst layers were coated on the carbon papers at 80 degrees C for one hour, at 120 degrees C for 30 minutes, and at 150 degrees C for 15 minutes to form cathodes (fuel electrodes). The loading amount of platinum cobalt in the cathodes was 3 mg/cm2. Platinum catalyst (2 g, 50 wt.% on carbon) and NMP (9 g) were introduced into a stirring vessel. The reaction mixture was stirred using a high-speed stirrer for two minutes. Then, a solution of polyvinylidenefluoride (0.005 g) in NMP (1 g) was added to the reaction solution, followed by stirring for two minutes, to make slurries for anode catalyst layers. The slurries for the anode catalyst layers were coated on carbon papers having microporous layers, using a bar coater. The loading amount of platinum in anodes was 1.4 mg/cm2. 3-Phenyl-3,4-dihydro-2H-benzo(e)(1,3)oxazine (65 parts by weight) and polybenzimidazole (35 parts by weight) were blended, and the blend was cured at 80-220 degrees C. Then, the cured product was impregnated with 85 wt.% phosphoric acid, at 80 degrees C for 4 hours to form electrolyte membranes. Here, the content of the phosphoric acid was 500 parts by weight. The electrolyte membranes were inserted between the cathodes and the anodes to manufacture membrane electrode assembly. Here, the cathodes and the anodes were not impregnated with phosphoric acid. In order to prevent gas permeation between the cathodes and the anodes, a stack of a 200 mu m Teflon (RTM: Polytetrafluoroethylene) film, used as a major gasket, and a 20 mu m Teflon (RTM: Polytetrafluoroethylene) film, used as a sub-gasket, were disposed at an interface between each electrode and each electrolyte membrane. Electric power was produced at 150 degrees C, under nonhumidified electrolyte membrane conditions, by passing hydrogen (flow rate: 100 ccm) through the anodes and air through the cathodes.