Roles of MWCNTs in a self-standing microporous layer for proton exchange membrane fuel cells

This study presents the effect of adding multiwalled carbon nanotubes (MWCNTs) to self-standing microporous layer (SSMPL) on water management and the oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). SSMPLs with various acetylene black (AB) and MWCNTs compositions are prepared and systematically characterized. The pore characteristics of the SSMPLs, including surface morphology, pore size distribution (PSD), and wettability, are studied. The current–potential characteristics of PEMFCs that adopt SSMPLs with different MWCNTs contents and convoluted oxygen reduction processes are analyzed using polarization and electrochemical impedance spectroscopy (EIS) techniques. These results suggest a transport mechanism for water through the SSMPLs modified by MWCNTs.