Chemistry – Electrochemistry - Hydrogen-oxygen fuel cells | e-Consult

A hydrogen-oxygen fuel cell is efficient because the reaction releases a significant amount of energy as heat during the formation of strong covalent bonds in water. Hydrogen gas (H₂) consists of two hydrogen atoms sharing a pair of electrons, forming a single covalent bond. Oxygen gas (O₂) consists of two oxygen atoms sharing a double bond. When these bonds form in water (H₂O), a large amount of energy is released. This released energy is harnessed to create an electric current. The energy released during bond formation is greater than the energy required to break the initial bonds in hydrogen and oxygen, resulting in a net release of energy as electricity. This contrasts with other energy conversion methods that may involve less efficient processes.