2. PAFC-1980
Two electrodes of
Porous(conducting
material) –to collect
charge

3. Phosphoric acid work as an
Electrolyte.
Supply For Electrode:
Positive-oxygen (or) air
Negative-Hydrogen (or)hydrogen
rich gas
Pores-Electrolyte &Electrode get a
contact in electrochemical reaction

4. Catalyst-accelerate
the reaction
Platinum-best catalyst
for both electrodes &
premium fuel cell.
Nickel-negative
electrode
Silver-positive
electrode
Catalyst-
platinum/nickel/silver
deposited on the
outer surface.
During the usage of
cell the catalyst
gradually lost its
activity.
Inactivaion-
impurities(sulphur)
in the fuel

5. At the Negative
electrode:
Hydrogen gas
Hydrogen ions+electrons
H2 2H+
+2eˉ
Electrons from negative
electrode flow through
the external load to
positive electrode.

6. H+ ions
migrate
negative to
positive
through
electrolyte.
On
reaching
the
positive
electrode-
interact
with O2 to
produce
water.
½ O2+2H+
+2eˉ
H2O
H2+1/2 O2
H2O

7. Operating
temperature=150°C-200°C
At
Atmospheric
Pressure the
ideal emf of
1.23V at 25°C
–reduces to
1.15V at
200°C.
The actual value less than
this & decrease with
current
Rated value
of current-
voltage lies
between
0.7V-0.8V.