Suggest two materials other than hydrogen that can be used as fuels in fuel cells.
Two materials other than hydrogen that can be used as fuels in fuel cells are methane and methanol.
Fuel cells are galvanic cells designed to convert the energy of combustion of fuels directly into electrical energy. These cells are highly efficient compared to thermal plants and are pollution-free in nature.
The development of new electrode materials, better catalysts and electrolytes has helped increase the efficiency of fuel cells using such alternative fuels. These have been used in automobiles on an experimental basis.
Explanation
The textbook explicitly mentions in Section 2.7 that fuel cells are designed to convert the energy of combustion of fuels like hydrogen, methane, methanol, etc. directly into electrical energy. Since the question asks for materials OTHER than hydrogen, the correct answers from the given context are methane and methanol.