Improving the performance and durability of low Pt-loaded MEAs by adjusting the distribution positions of Pt particles in cathode catalyst layer

Abstract

The durability and performance of membrane electrode assembly (MEA) compose the bottleneck of fuel cells industrialization. In this paper, the effects of Pt particles distribution positions in the catalyst layer of MEA are studied. Polarization curves are carried out to evaluate the performance of MEAs with different Pt dispersion. It is found that when the Pt particles in the cathode catalyst layer are dispersed close to the membrane, under the same relative humidity, the MEA has better performance (0.819 W/cm2) because of the smaller charge transfer resistance and mass transfer resistance. At the same time, by comparing the changes of the oxygen transport resistance in the catalyst layer, it is shown that this structure makes it easier for oxygen molecules to be transported to the surface of the Pt particles. Meanwhile, the accelerated stress test is conducted to explore the durability of these MEAs. The result shows that when Pt particles are dispersed near the membrane, the stability of MEA is the same as that of MEA when Pt particles are evenly distributed in the catalyst layer. Therefore, by dispersing the Pt particles in the cathode catalyst layer near the membrane, the performance and durability of MEAs can be effectively improved.