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CHEG 295/320: Fuel Cell Engineering (Fall 2004)
Homework 3- addendum: Electrode Kinetics
Due Oct. 13th 2004
Section 4.
I (mA/cm2)
0
10
20
40
60
80
100
200
250
300
350
400
450
500
E (V) – already corrected for resistance effects.
0.83682
0.77368
0.72337
0.67431
0.64357
0.61984
0.59856
0.53151
0.50378
0.47941
0.45611
0.4319
0.40615
0.38133
il = 600 mA/cm2
Using this data, obtain “kinetic” parameters using both the unmodified
Tafel equation and the Tafel equation modified to correct for mass
transfer. In doing so, compare 2 ranges of current density:
1. from 10 mA/cm2 to 100 mA/cm2
2. Entire current range.
Where is the effect of mass transfer is most pronounced. Why? (2 lines
max.)
Finally, if the data used for sections 2 and 3 were obtained on pure
oxygen (100% oxygen), estimate the oxygen concentration used to
obtain the above data – Just provide the number. (Hint, it is not air)