Page 33 - Introduction to Transfer Phenomena in PEM Fuel Cells

22 Introduction to Transfer Phenomena in PEM Fuel Cells
converting the energy contained in hydrogen into electricity. The second is a
reaction that can take place if carbon monoxide is present in the fuel (it
therefore does not occur if the battery is supplied with pure hydrogen), it is
favorable to the battery since it also makes it possible to produce electricity
[BLU 07, BOU 07, SPI 07]:
– anode:
+
+
+
H (g) CO 2− ⎯⎯→ H O(g) CO (g) 2e − [1.10]
2
3
2
2
– cathode:
1 O(g) CO(g) 2e ⎯⎯→ CO 2− [1.11]
−
+
+
2 2 2 3
– overall reaction:
H (g) + 1 O (g) CO (g) ⎯⎯→ H O(g) CO (g) [1.12]
+
+
2
2 2 2 2 2
Figure 1.9 shows the operating principle of a MCFC.

Figure 1.9. Operating principle of a MCFC