Improving anion exchange membrane fuel cell performance via enhanced ionomer-carbon interaction in cathode catalyst layers with carbon-supported Pt catalyst using a pyrene carboxyl acid coating

While there have been substantial strides in anion exchange membrane and ionomer, engineering the catalyst layers (CLs) of anion exchange membrane fuel cells (AEMFCs) is still an unexplored domain despite its significance. Conventional anion exchange ionomers (AEIs) tend to be locally agglomerated in the CLs due to their weak interaction with the carbon support of catalyst, resulting in pore clogging in the CLs. Herein, we report that the coating of pyrene carboxyl acid (PCA) on the carbon surface increases ionomer-carbon interaction. PCA has a strong interaction with carbon surface via p-p interaction and with AEI via coulombic interaction. The use of PCA prevents the aggregation of ionomer chains, leading to homogeneous ionomer distribution and meso-porous CL structure. Due to the expanded catalyst/ionomer interface and promoted O2 transport, PCA coating improves the electrochemical performance of AEMFC. Controlling the ionomer-carbon interaction opens a new avenue for realizing high-performance AEMFCs.