1. Hydrogen Storage: Hydrogen is stored in onboard tanks in gaseous or liquid form. The source of hydrogen can vary, such as from compressed hydrogen gas or by extracting it from a liquid fuel like methanol.
2. Air Intake: Oxygen is drawn from the surrounding air, which serves as the oxidizer in the fuel cell reaction.
3. Fuel Cell Stack: The fuel cell stack is the heart of the fuel cell system. It consists of multiple individual fuel cells arranged in a stack. Each fuel cell contains an electrolyte membrane, typically a Proton Exchange Membrane (PEM) in automotive applications.
4. Electrochemical Reaction: When hydrogen gas is supplied to one side of the fuel cell stack (anode), and oxygen from the air is supplied to the other side (cathode), a chemical reaction occurs at the catalyst-coated electrodes.
Anode reaction: 2H2 (hydrogen) → 4H+ (protons) + 4e- (electrons)
Cathode reaction: O2 (oxygen) + 4H+ (protons) + 4e- (electrons) → 2H2O (water)