Chemistry - 7 Energy Changes - 7.6 Fuel Cells

Alkaline fuel cell: hydrogen half equation

H₂ + 2OH⁻ → 2H₂O + 2e⁻

Alkaline fuel cell: oxygen half equation

O₂ + 2H₂O + 4e⁻ → 4OH⁻

Acidic fuel cell: hydrogen half equation

H₂ → 2H⁺ + 2e⁻

Acidic fuel cell: oxygen half equation

O₂ + 4H⁺ + 4e⁻ → 2H₂O

Alkaline fuel cell: full equation

2H₂ + O₂ → 2H₂O

Acidic fuel cell: full equation

2H₂ + O₂ → 2H₂O

Advantages of hydrogen fuel [3]:

• no electrical recharging

• no pollutants

• range of sizes

Disadvantages of hydrogen fuel [3]:

• highly flammable

• produced by non-renewable resources

• difficult to store