SK025 Chapter 2 Hydrogen Fuel

A fuel cell uses the chemical energy of hydrogen or other fuels to cleanly and efficiently produce electricity. If hydrogen is the fuel, the only products are electricity, water, and heat. For hydrogen fuel, there are two types, acidic medium and basic medium. Most common hydrogen fuel is in acidic medium.

hydrogen fuel

Hydrogen fuel (acidic medium) 
  • ANODE: H2(g) → 2H+ + 2e- 
  • CATHODE: O2 (g) + 4H+(aq) + 4e- → 2H2O(l) 
  • The overall equation : 2H2 (g) + O2 (g) → 2H2O (l) 

Hydrogen fuel (basic medium) 
  • ANODE: 2H2 (g) + 4OH- (aq) → 4H2O (l) + 4e- 
  • CATHODE: O2 (g) + 2H2O (l) + 4e- → 4OH- (aq) 
  • OVERALL: 2H2 (g) + O2 (g) → 2H2O (l)