Solutions to exercises
295
• at the cathode 2O 2 + 8e m 4O
2−
The overall reaction is
CH 4 + 2O 2 m CO 2 + 2H 2 O
2 Partial electrochemical oxidation
• at the anode
CH 4 + 3O
2−
m CO + 2H 2 O + 6e
• at the cathode 2
3
O 2 + 6e m 3O
2−
The overall reaction is
CH 4 + 2
3
O 2 m CO + 2H 2 O
b. For an arbitrary hydrocarbon C n H m
2 Total electrochemical oxidation
• at the anode
C n H m +
n
2
m
2
+
^
hO 2− $ nCO 2 +
m
2 H 2 O + (4n + m)e
• at the cathode
n
m
4
+
^
hO 2 + (4n + m)e $
n
2
m
2
+
^
hO 2−
The overall reaction is
C n H m + n
m
4
+
^
hO 2 $ nCO 2 +
m
2 H 2 O
Applied to propane
• at the anode
C 3 H 8 + 10 O
2−
$ 3CO 2 + 4H 2 O + 20e
• at the cathode
5O 2 + 20e $ 10O
2−
The overall reaction is
C 3 H 8 + 5O 2 $ 3CO 2 + 4H 2 O
Application to but-2-ene
• at the anode
C 4 H 8 + 12O
2−
$ 4CO 2 + 4H 2 O + 24e
• at the cathode
6O 2 + 24e $ 12O
2−