METHOD FOR MANUFACTURING ELECTRODE CATALYST, ELECTRODE CATALYST, COMPOSITION FOR GAS DIFFUSION ELECTRODE FORMATION, GAS DIFFUSION ELECTRODE, MEMBRANE-ELECTRODE ASSEMBLY (MEA) AND FUEL BATTERY STACK

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing an electrode catalyst, by which an electrode catalyst of which the content of chlorine (Cl) species is sufficiently reduced can be obtained through a simple operation even in the case of using an electrode catalyst precursor including a high density of chlorine as a raw material.SOLUTION: A method for manufacturing an electrode catalyst having a core-shell structure including a core part formed on a carrier and a shell part formed to cover at least part of the surface of the core part comprises: the first step (1) of preparing a first liquid arranged by adding, to ultrapure water, an electrode catalyst precursor (I) manufactured by use of a material including chlorine (Cl) species, of which the concentration of chlorine (Cl) species measured according to fluorescent X-ray spectroscopy is equal to or larger than a first chlorine(Cl) species concentration; and the second step (2) of preparing a second liquid by performing the rinse and filtration of the electrode catalyst precursor (I) with ultrapure water to obtain an electrode catalyst precursor (II), provided that the rinse is performed until the electric conductivity &rgr; of resultant filtrate is equal to or less than a first set value, and dispersing the electrode catalyst precursor (II) in ultrapure water.