Chemistry – Physical chemistry | e-Consult

Working of a Fuel Cell:

A fuel cell is an electrochemical device that converts the chemical energy of a fuel (typically hydrogen) and an oxidant (typically oxygen) into electrical energy. It operates by facilitating the electrochemical reaction between the fuel and the oxidant.

Key Components:

• Anode: Where the fuel is oxidized.
• Cathode: Where the oxidant is reduced.
• Electrolyte: A substance that allows the transport of ions between the anode and cathode. It can be either acidic, alkaline, or a polymer membrane.
• Catalyst: A material (often platinum) that speeds up the electrochemical reactions.

Electrochemical Reactions:

A typical hydrogen fuel cell uses hydrogen (H₂) as the fuel and oxygen (O₂) as the oxidant. The overall reaction is:

Anode (Oxidation): Hydrogen is oxidized to protons (H⁺) and electrons (e^-).

Cathode (Reduction): Oxygen is reduced to hydroxide ions (OH^-) and electrons (e^-).

Role of the Electrolyte:

The electrolyte provides a medium for the transport of ions between the anode and cathode. This completes the electrical circuit. The electrolyte allows the protons (H⁺) to migrate from the anode to the cathode, enabling the formation of water. The type of electrolyte used depends on the type of fuel cell (e.g., PEM fuel cell uses a polymer membrane electrolyte).