Although Dr. Keller is most interested in the production of biofuels from cellulose, there are other alternatives to fossil fuels. Hydrogen gas is one such alternative. Like gasoline and alcohol, it can be burned in a combustion engine. However, the combustion of hydrogen does not produce carbon dioxide or toxic air pollutants. Instead, it produces water vapor.

Hydrogen can be obtained through several chemical reactions. One process uses electrical energy to split water molecules into their basic components. Known as electrolysis, the process is used to generate hydrogen gas that can later be used as a cleaner fuel. In this activity, you will explore electrolysis and generate hydrogen gas.