Fuel cells, as devices for direct conversion of the chemical energy of a fuel into
electricity by electrochemical reactions, are among the key enabling technologies for the transition
to a hydrogen-based economy. Among the various types of fuel cells, polymer electrolyte
membrane fuel cells (PEMFCs) are considered to be at the forefront for commercialization for
portable and transportation applications because of their high energy conversion efficiency and low
pollutant emission. Cost and durability of PEMFCs are the two major challenges that need to be
addressed to facilitate their commercialization. The properties of the membrane electrode assembly
(MEA) have a direct impact on both cost and durability of a PEMFC.
An overview is presented on the key components of the PEMFC MEA. The success of the MEA
and thereby PEMFC technology is believed to depend largely on two key materials: the membrane
and the electro-catalyst. These two key materials are directly linked to the major challenges faced in
PEMFC, namely, the performance, and cost. Concerted efforts are conducted globally for the past
couple of decades to address these challenges. This chapter aims to provide the reader an overview
of the major research findings to date on the key components of a PEMFC MEA.