▎ 摘　　要

NOVELTY - A membrane-electrode assembly comprises a polymer electrolyte membrane and electrode catalyst layers positioned on both surfaces of the polymer electrolyte membrane, and at least one of the polymer electrolyte membrane and the electrode catalyst layers contain a metal oxide of a perovskite structure containing cation (A) chosen from sodium, potassium, rubidium, gold, calcium, strontium, barium, lead, lanthanum, praseodymium, neodymium, bismuth, cerium, and thorium, and the cation (B) chosen from at least one of lithium, copper, magnesium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, rhodium, ruthenium, platinum, niobium, tantalum, molybdenum, and tungsten. USE - Membrane-electrode assemble for fuel cell (claimed) used as power generation system in portable power supply of communication equipment and military equipment. ADVANTAGE - The membrane-electrode assembly has excellent durability, and has high current, and power density in high and low humidity condition. DETAILED DESCRIPTION - A membrane-electrode assembly comprises a polymer electrolyte membrane and electrode catalyst layers positioned on both surfaces of the polymer electrolyte membrane, and at least one of the polymer electrolyte membrane and the electrode catalyst layers contains a metal oxide of a perovskite structure of formula (I), AxB'yOz, where x is 0.667-2, y is 1-2, z is 3-7, A and B' are cations. The cation (A) having greater ionic radius than that of cation (B') is formed by sharing a vertex in the oxide. The cation (A) is at least one selected from sodium (Na+), potassium (K+), rubidium (Rb+), gold (Ag+), calcium (Ca2+), strontium (Sr2+), barium (Ba+2), lead (Pb2+), lanthanum (La3+), praseodymium (Pr3+), neodymium (Nd3+), bismuth (Bi3+), cerium (Ce4+), and thorium (Th4+). The cation (B') is at least one selected from lithium (Li+), copper (Cu2+), magnesium (Mg2+), titanium (Ti3+), vanadium (V3+), chromium (Cr3+), manganese (Mn3+), iron (Fe4+), cobalt (Co3+), nickel (Ni3+), rhodium (Rh3+), titanium (Ti4+), manganese (Mn4+), ruthenium (Ru4+), platinum (Pt4+), niobium (Nb5+), tantalum (Ta5+), molybdenum (Mo6+), and tungsten (W6+).