Quantifying potential losses of non-Pt MEAs for gas-phase HBr PEM electrolyzer to produce hydrogen

Gas-phase HBr can be converted to hydrogen and bromine in a proton exchange membrane (PEM) electrolyzer. However, due to high cost and the poisoning of bromine and bromide ions on Pt electrodes, non-Pt MEAs (membrane electrode assembly) need to be developed and evaluated. In this paper, RuO2, carbon (Vulcan XC 72R) and TiO2–Nb (10% wt.) are prepared as anodes, and IrO2/C and MoS2 are prepared as cathodes for incorporation into MEAs. The individual electrodes in these MEAs are then evaluated by de-convoluting the individual voltage losses in-situ from the total electrolyzer voltage. On the anode, Pt, Vulcan XC 72R, TiO2–Nb (10% wt.) and RuO2 are all found to have comparable activity toward bromine evolution. On the cathode, Pt was more active toward the hydrogen evolution reaction (HER) compared to IrO2/C, and both were far superior to MoS2.