Polymer electrolyte membrane fuel cells [PEMFCs] are regarded as a power source for fuel cell vehicles due to their high power density, high efficiency, and low operating temperature. The development of a fuel cell vehicle has been accelerated because of environmental problems, including global warming caused by carbon dioxide emissions and air pollution due to excessive consumption of fossil fuels. Research of the catalyst and membrane is required in order to enhance lifetime and durability for the commercialization of PEMFCs [1
]. Currently, the corrosion of carbon is an important issue as it improves the lifetime and durability of the catalyst [5
]. The structural breakdown by electrochemical carbon corrosion causes migration and agglomeration of the Pt particles. As a result, cell performance decreases due to a reduction in the electrochemical surface area. Carbon black [CB] is the most widely used catalyst support, but carbon corrosion occurs with long-term PEMFC operation [8
]. Carbon corrosion is accelerated due to fuel starvation and repeated on/off cycles. When lack of fuel is generated, the electrolysis reaction of the water and carbon oxidization reaction are generated in the anode to supply the proton and electrons for the cathode oxygen reduction reaction. The carbon corrosion mechanism occurs according to the following reaction:
As a result, a reverse voltage is generated by alternating between the anode and cathode voltages [10–17]. Therefore, research on carbon support is required to improve durability.
Each type of carbon has a different performance and durability, but carbon characteristics can also affect the corrosion rate [2, 18, 19]. Cell performance will decrease due to the increase in cell resistance with reduced thickness of the catalyst layer and electric contact of the current collector caused by carbon corrosion . Recently, graphitized carbon types, such as carbon nanofibers [CNFs], carbon nanotubes, and graphene, have been studied. Graphitic carbons are known to have high corrosion resistance as they have good thermal and electrochemical stability [19, 21–25]. CNFs have higher electric conductivity and durability than commercial CBs as catalyst support materials [19, 26]. However, it is difficult to synthesize platinum nanoparticles for loading and dispersion. CNFs with different structure and morphology have been used for electrode materials fabricated via various synthesis methods in order to achieve different surface chemistries [27–31]. CNFs are potentially suitable materials for high platinum loading and dispersion due to their many functional groups. The number of functional groups increases with increasing surface oxidation treatment time, producing a hydrophobic carbon surface which accelerates carbon corrosion .
In this study, we synthesized a catalyst with Pt particles of high loading and distribution on the CNFs. Membrane electrode assemblies [MEAs] were prepared using the Pt/CNF catalyst, and the performance changes caused by fuel starvation were evaluated via electrochemical analysis.