Question

Name any two materials other than hydrogen that can be used as fuel in fuel cells.

Hint:

Think of simple organic fuels such as methane or methanol that can be oxidised at the anode of a fuel cell.

Answer 1

Step 1: Recall what a fuel cell does:
A fuel cell turns the chemical energy of a fuel directly into electrical energy.
The fuel burns in oxygen, but it does so in a cell and not in a flame.
Hydrogen is the best known fuel, but it is not the only one.

Step 2: Choose suitable fuels:
A fuel for such a cell must be able to give up electrons at the anode.
It should be cheap and easy to supply as a gas or a liquid.
Methane (\( \mathrm{CH_4} \)) and methanol (\( \mathrm{CH_3OH} \)) meet these needs.

Step 3: Show the overall reaction:
For methanol the overall cell reaction is
\[ \mathrm{2CH_3OH + 3O_2 \rightarrow 2CO_2 + 4H_2O} \]
For methane it is
\[ \mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O} \]

Final Answer:
Two fuels other than hydrogen are methane and methanol. Ethanol, carbon monoxide and hydrazine are also used. \[ \boxed{\text{Methane and methanol}} \]