Electrode Reactions in Hydrogen Fuel Cells Flashcards

All 6 cards in this deck

At which electrode of a hydrogen fuel cell is hydrogen oxidised?

The negative electrode, where hydrogen loses electrons.

Write the half equation for the reaction at the negative electrode of an acidic hydrogen fuel cell.

$\mathrm{H_2} \rightarrow 2\mathrm{H^+} + 2\mathrm{e^-}$

Write the half equation for the reaction at the positive electrode of an acidic hydrogen fuel cell.

$\mathrm{O_2} + 4\mathrm{H^+} + 4\mathrm{e^-} \rightarrow 2\mathrm{H_2O}$

Write the half equation for the reaction at the negative electrode of an alkaline hydrogen fuel cell.

$\mathrm{H_2} + 2\mathrm{OH^-} \rightarrow 2\mathrm{H_2O} + 2\mathrm{e^-}$

Write the half equation for the reaction at the positive electrode of an alkaline hydrogen fuel cell.

$\mathrm{O_2} + 2\mathrm{H_2O} + 4\mathrm{e^-} \rightarrow 4\mathrm{OH^-}$

True or false? In a hydrogen fuel cell, hydrogen is reduced at the negative electrode.

False. Hydrogen is oxidised at the negative electrode — it loses electrons.