Aqueous solution to simulate the operation environment of
proton exchange membrane fuel cells (denoted as simulated solution)
consists of 98% H2SO4 and 48% HF diluted in de-ionized water.
The final composition was 12 ppm H2SO4, 1.8 ppm HF, and deionized
water. The pH value of this simulated solution was 3.35,
that is close to the fuel cell environment [34]. The strong acid solution
used in this study also consists of 98% H2SO4 and 48% HF
diluted in de-ionized water. The final composition is 1.0 M H2SO4,
1.8 ppm HF, and de-ionized water. An acetic acid solution with pH
of 5.0 was employed as weak acid.