A Pt content and pore structure gradient distributed catalyst layer to improve the PEMFC performance

The catalyst layer is a key component in the proton exchange membrane fuel cell (PEMFC) for it is where the conversion of fuel into electricity takes place. Traditionally, electrocatalyst is uniformly distributed in the catalyst layers of the membrane electrode assembly (MEA) and the high Pt consumption in catalyst layers blocks the widely use of PEMFC. Here we proposed a Pt content and pore structure gradient distributed, two-layer catalyst layer for PEMFC to improve the MEA performance. Energy-dispersive X-ray (EDX) spectroscopy results show Pt nanoparticles gradient distributed on the vertical direction of catalyst layer. The pore size in the Pt poor layer is larger than that in the Pt rich layer, and this structure can improve the Pt utilization and enhance the mass transfer in the catalyst layer. The single cell test result shows this new MEA has a better performance (11%) than the traditional MEA.