
444 Electrochemically Enabled Sustainability
in alkaline and cathode in acid. The overall cell voltage is 0.4 V, the same
as a single pH fuel.
Although no increase in voltage was observed, this BPM fuel cell has water
generation distributed at the cathode, anode, and water consumed at the bipo-
lar junction. This avoids the common problem of ooding at the air cathode
where water is generated in a single pH fuel cell. In the other conguration of
the hybrid fuel cell (Figure 11.9b), the pH environments are reversed for anode
and cathode and the BPM is under forward bias. The thermodynamic cell volt-
age for both of these hybrid fuel cells are the ...