Method for preparing pyrochlore oxide, polymer electrolyte fuel cell, fuel cell system, and method for producing electro catalyst for fuel cell

摘要

The present invention provides a method for preparing a pyrochlore type oxide having a larger specific surface area, a polymer electrolyte fuel cell and a fuel cell system improved in power generation efficiency and capable of being produced more inexpensively, and a method for producing an electro catalyst for a fuel cell, which electro catalyst has a larger specific surface area, is relatively inexpensive, and has high electrode activity per unit mass. A method for preparing a pyrochlore type oxide represented by A₂B₂O_7-Z wherein A and B represent a metal element, Z represents a number of 0 or more and 1 or less, A includes at least one selected from the group consisting of Pb, Sn, and Zn, and B includes at least one selected from the group consisting of Ru, W, Mo, Ir, Rh, Mn, Cr, and Re, wherein the pyrochlore type oxide is produced by a reaction of a halide or nitrate of A with an alkali salt of a metal acid of B. A method for producing an electro catalyst for a fuel cell, including producing this oxide in this manner. A polymer electrolyte fuel cell and a fuel cell system including this oxide.