ELECTRODE CATALYZER FOR FUEL CELL, FUEL CELL AIR ELECTRODE EMPLOYING ELECTRODE CATALYZER, AND CATALYTIC ACTIVITY EVALUATION METHOD FOR ELECTRODE CATALYZER

摘要

In a powder-form electrode catalyze for a fuel cell which comprises cataly st particles that contain platinum, and an electrically conductive support supporting the catalyst particles, the ratio between a mean value D111 of crystallite diameters of catalyst particles in a direction perpendicular to a (111) crystal face and a mean value D100 of crystallite diameters of the catalyst particles in a direction perpendicular to a (100) crystal face is D100/D11 < 1, and a mean crystallite diameter of th e catalyst particles is at most 5 nm. Due to a large surface area that functions as a catalyst and a great proportion of the catalyst particles that have (100) crystal faces present on surfaces, the electrode catalyze has high oxygen reduction activity.