Hydrogen–oxygen fuel cells represent a significant technological improvement over conventional internal combustion engines and traditional secondary cells for vehicular propulsion. Which of the following statements correctly explains a fundamental chemical or operational advantage of a hydrogen–oxygen fuel cell compared to these traditional systems?
Unlike secondary cells, a fuel cell maintains a constant voltage during operation because its reactants are continuously supplied from an external source, ensuring the concentrations of species at the electrodes remain constant.
Fuel cells achieve a higher thermodynamic efficiency than combustion engines because their operation is governed by the Carnot cycle, which exploits the high operating temperature of the cell.
A hydrogen–oxygen fuel cell is carbon-neutral over its entire lifecycle because the only direct product formed during its operation is water.
The catalytic platinum electrodes in a fuel cell undergo reversible sacrificial oxidation, prolonging the cell lifetime compared to lithium-ion electrodes which suffer from irreversible transition metal depletion.