7 c]Describe the construction and working of Methanol –Oxygen fuel cell.
“Fuel cell is a galvanic cell in which chemical energy of a fuel is directly converted into electrical energy by means of redox reactions involved with oxidants”.
Cell Representation: CH3OH│Pt│H+│Ag│O2
It is an example of a liquid fuel cell. Construction of fuel cell is shown in figure. Because the storage and safe handling of hydrogen gas is troublesome, methanol is used instead of hydrogen gas as a reactant. Platinized (catalyst) porous carbon acts as anode. Hollow porous carbon tube impregnated with mixed oxides of Ag, Co and Al (catalyst) acts as cathode. The oxidant is the oxygen or air. Electrolyte is 1M sulphuric acid.
Anode | CH3OH + H2O →CO2 + 6H++6e- |
Cathode | 3/2O2 + 6H++6e- → 3H2O |
Overall | CH3OH + 3/2O2 → 2H2O + CO2 |