Measurement of Oxygen Gas Transport Resistance in Cathode Catalyst Layers of PEFC

Abstract

Some in-situ techniques measuring limiting current in order to analyze the reactant gas transport structure in the cathode of PEFC have been proposed. By these methods, it has been found that the reactant gas transport resistance in cathode catalyst layers (CLs) (RCL ) was separated into two components, diffusion resistance of catalyst pore (Rpore ) and diffusion resistance around Pt surface (RPt ). This paper describes a method to determine Rpore and RPt by means of only measuring limiting currents, without any additional measurements. RPt and Rpore with different catalyst types and various ionomer carbon ratios (I/C) were measured and it was found that these parameters depend on I/C.