Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: A polymer electrolyte membrane which comprises a polymer electrolyte having sulfonic acid groups, and contains any one of the following (a) to (c): (a) cerium ions and an organic compound (X) capable of forming an inclusion compound with cerium ions; (b) an inclusion compound (Y) comprising the organic compound (X) including cerium ions; and (c) at least one of cerium ions and the organic compound (X), and the inclusion compound (Y).

Abstract: An electrolyte membrane which comprises a cation exchange membrane made of a polymer having cation exchange groups and contains cerium ions is used as an electrolyte membrane for a polymer electrolyte fuel cell. In a case where the cation exchange membrane has sulfonic acid groups, the sulfonic acid groups are ion-exchanged, for example, with cerium ions so that cerium ions are contained preferably in an amount of from 0.3 to 20% of —SO3? groups contained in the cation exchange membrane. A membrane for a polymer electrolyte fuel cell capable of power generation in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas and capable of stable power generation over a long period of time, can be provided.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane which comprises a cation exchange membrane made of a polymer having cation exchange groups and contains cerium ions is used as an electrolyte membrane for a polymer electrolyte fuel cell. In a case where the cation exchange membrane has sulfonic acid groups, the sulfonic acid groups are ion-exchanged, for example, with cerium ions so that cerium ions are contained preferably in an amount of from 0.3 to 20% of —SO3? groups contained in the cation exchange membrane. A membrane for a polymer electrolyte fuel cell capable of power generation in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas and capable of stable power generation over a long period of time, can be provided.

Abstract: An electrolyte membrane which comprises a cation exchange membrane made of a polymer having cation exchange groups and contains cerium ions is used as an electrolyte membrane for a polymer electrolyte fuel cell. In a case where the cation exchange membrane has sulfonic acid groups, the sulfonic acid groups are ion-exchanged, for example, with cerium ions so that cerium ions are contained preferably in an amount of from 0.3 to 20% of —SO3? groups contained in the cation exchange membrane. A membrane for a polymer electrolyte fuel cell capable of power generation in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas and capable of stable power generation over a long period of time, can be provided.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane which comprises a cation exchange membrane made of a polymer having cation exchange groups and contains cerium ions is used as an electrolyte membrane for a polymer electrolyte fuel cell. In a case where the cation exchange membrane has sulfonic acid groups, the sulfonic acid groups are ion-exchanged, for example, with cerium ions so that cerium ions are contained preferably in an amount of from 0.3 to 20% of —SO3? groups contained in the cation exchange membrane. A membrane for a polymer electrolyte fuel cell capable of power generation in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas and capable of stable power generation over a long period of time, can be provided.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte membrane is prepared from a liquid composition comprising at least one member selected from the group consisting of trivalent cerium, tetravalent cerium, bivalent manganese and trivalent manganese; and a polymer with a cation-exchange group. The liquid composition is preferably one containing water, a carbonate of cerium or manganese, and a polymer with a cation-exchange group, and a cast film thereof is used as an electrolyte membrane to prepare a membrane-electrode assembly. The present invention successfully provides a membrane-electrode assembly for polymer electrolyte fuel cells being capable of generating the electric power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas, and being capable of stably generating the electric power over a long period of time.

Abstract: An electrolyte material for polymer electrolyte fuel cells, which is made of a polymer containing repeating units based on a fluoromonomer having a radical polymerization reactivity, wherein the repeating units contain a 5-membered ring (which may contain 1 or 2 oxygen atoms), of which at least one carbon atom is contained in the main chain of the polymer, and an ionic group such as a sulfonic acid group which is bonded to the 5-membered ring directly or via a perfluoroalkylene group having a linear or branched structure; and the polymer has a softening temperature of at least 120° C.

Abstract: An electrolyte membrane for a polymer electrolyte fuel cell, which comprises an ion exchange membrane made of a fluoropolymer having a softening temperature of at least 90° C. and having acidic groups, and contains cerium atoms.

Abstract: A polymer electrolyte membrane which comprises a polymer electrolyte having sulfonic acid groups, and contains any one of the following (a) to (c): (a) cerium ions and an organic compound (X) capable of forming an inclusion compound with cerium ions; (b) an inclusion compound (Y) comprising the organic compound (X) including cerium ions; and (c) at least one of cerium ions and the organic compound (X), and the inclusion compound (Y).

Abstract: To provide an electrolyte membrane for a polymer electrolyte fuel cell, capable of generating power in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas and capable of generating stable power over a long period of time. A membrane used as an electrolyte membrane for a polymer electrolyte fuel cell, which comprises a cation exchange membrane made of a fluorinated polymer having cation exchange groups and having an ion exchange capacity of from 1.0 to 2.5 meq/g dry polymer, wherein some of the cation exchange groups are ion-exchanged with at least one type of ions selected from the group consisting of cerium ions and manganese ions.

Abstract: An electrolyte membrane which comprises a cation exchange membrane made of a polymer having cation exchange groups and contains manganese ions is used as an electrolyte membrane for a polymer electrolyte fuel cell. In a case where the cation exchange membrane has sulfonic acid groups, the sulfonic acid groups are ion-exchanged, for example, with manganese ions so that manganese ions are contained preferably in an amount of from 0.5 to 30% of —S03? groups contained in the cation exchange membrane.

Abstract: An electrolyte membrane which comprises a cation exchange membrane made of a polymer having cation exchange groups and contains cerium ions is used as an electrolyte membrane for a polymer electrolyte fuel cell. In a case where the cation exchange membrane has sulfonic acid groups, the sulfonic acid groups are ion-exchanged, for example, with cerium ions so that cerium ions are contained preferably in an amount of from 0.3 to 20% of —SO3? groups contained in the cation exchange membrane. A membrane for a polymer electrolyte fuel cell capable of power generation in high energy efficiency, having high power generation performance regardless of the dew point of the feed gas and capable of stable power generation over a long period of time, can be provided.