acid, sodium hydroxide, potassium hydroxide, sodium citrate (tribasic),
salicylic acid, potassium phosphate (dibasic), potassium phosphate
(monobasic), sodium hypochlorite solution (10–15%), and sodium
nitroferricyanide(III) dihydrate were purchased from Millipore Sigma
(Burlington, Massachusetts). Sustainion X37–50 grade RT, PiperION-A80,
Fumasep FAA 3–50, and isomolded graphite plates were purchased
from The Fuel Cell Store (College Station, Texas). Nafion 211 and
Nafion 212 were purchased from Fuel Cell Earth (Woburn, Massachusetts).
Celgard 3401 and Celgard 2400 were purchased from Celgard (Charlotte,
North Carolina). All solutions were made using deionized (DI) water
(>18.0 MΩ·cm, Milli-Q Gradient System, Millipore Sigma).
Custom glass H-cells were purchased from Adams & Chittenden Scientific
Glass (Berkeley, California).