
363Fuel Cell Components and Design
anode, the hydrogen gas ionizes, releasing electrons and creating H
+
ions (or
protons). This reaction releases energy. At the cathode, oxygen reacts with
electrons taken from the electrode, and H
+
ions from the electrolyte, to form
water.
The electrochemical reactions occurring in PAFCs are
At the anode: H
2
→ 2H
+
+ 2e
–
(9.9)
At thecathode:O+2He
+
2
1
+→
−
(9.10)
Overall cell reaction H
2
+ O → H
2
O. (9.11)
In the PAFC, the electrochemical reactions take place on highly dispersed
electrocatalyst particles supported on carbon black. As with the PEMFCs,
platinum (Pt) or Pt alloys are used as the catalyst at both ...