Both low- and high-temperature processes
have pros and cons. For instance, the high-temperature decal
method requires conversion of the membrane from proton
(Hþ) to Naþ-form to enhance its thermal stability, which can
withstand hot-pressing temperatures of as high as 200 C.
Then, reprotonation of the MEA is needed before use in a fuel
cell. That makes the overall process more complicated and
time consuming. The low-temperature decal method is relatively
simple as it can use the membrane in proton form but it
requires hot-pressing under high pressure for an extended
duration to ensure a good catalyst transfer rate. Subjecting an
MEA to very high pressure or to a long duration of hot-pressing
can have adverse effects on performance.