Several groups have reported evidence for both hydrogen cyanide (HCN) and cyanogen ((CN)2) gas release in PBAs at high voltages, suggesting a reductive coupling process (similar to how oxygen is released in the Li-layered oxides) at high voltages as the cause propose that the acidity of the working electrode environment significantly impacts the likelihood of (CN)2 release . However, to our knowledge no detailed studies have been published on the mechanism or extent of (CN)2 release in PW electrodes under varying cycling conditions. Most studies report hydrogen (H2) to be the dominant evolving gas, with several studies surprisingly showing a relatively large peak upon discharge . Continuous evolution of H2 in a cell detrimentally impacts both capacity (through loss of electrolyte) and safety, therefore a more in depth understanding of this phenomenon is desired.