A hydrogen fuel cell device that processes pure hydrogen to generate an electric current. In most common applications, The hydrogen is placed on one side of a gaseous barrier. Oxygen atoms in the air can cross the barrier but cannot transfer their electrons across. Electrons are transferred to a conductor and flow to the other side of the barrier as electricity that can be harnessed and stored. When oxygen and hydrogen atoms They come together to form water. The only emissions of a hydrogen fuel cell are electricity and pure water. Fuel cell electric vehicles (FCEVs) such as the Toyota Mirai use hydrogen fuel cells for energy to power their electric motors.