| dc.description.abstract | The fabrication of an ideal electrode material for fuel cell application that can maintain an
optimal water content in both low and high relative humidity (RH) conditions has been studied
by many research groups. Previous work by Eastcott et. al has shown great promise when using
sulfonated ceramic carbon electrodes (CCEs) on the cathode of a PEMFC in low relative
humidity (RH) environments though increased water retention. Through the sol-gel method the
use of tetraethylorthosilicate (TEOS) and a small amount of 3-(trihydroxysilyl) propane-1-
sulfonic acid (TPS) as the ionomer demonstrated increased porosity, better durability, and better
fuel cell performance at low RH when compared to the traditional Nafion ionomer material.
In this work the sulfonated CCE material developed by Eastcott and Easton will be
replaced with a more ion conductive sulfonated organosilane monomer component. TPS was
replaced with 4-(2-(trihydroxysilyl)ethyl) benzenesulfonic acid (TEBS) and mixed with TEOS
and compared to the previous TPS/TEOS system as well as the traditional Nafion ionomer
electrode. The sulfonated CCEs were characterized using BET surface area analysis,
thermogravimetric analysis, SEM, and TEM. The electrodes were then evaluated in both halfcell
and full cell environments. Half-cell data showed an increased ECSA with TEBS when
compared to the Nafion ionomer, while full cell data determined a decreased performance at both
high and low relative humidities through polarization curves when compared to the TPS/TEOS
and Nafion ionomers. The results obtained have determined that an optimization of the
sulfonated to unsolfonated ratio has to be altered in order to gain a performance similar to that of
the TPS based ionomer. The total silane loading was then decreased while the TEBS loading was
increased and this showed an increase in fuel cell performance more comparable to the
TPS/TEOS ionomer system. | en |
