Hydrogen as a Clean Energy Source: Benefits, Challenges, and History

Hydrogen, the most abundant element in the universe, has garnered interest as an energy source and carrier due to its unique properties. Molecular H2 is lightweight, storable, and possesses an exceptionally high gravimetric energy content compared to other common fuels (120 MJ kg-1). The idea of utilizing hydrogen for energy purposes is not new, with recommendations dating back several decades. In 1971, Jones proposed the use of liquid hydrogen as a potential replacement for fossil fuels. Subsequently, Salzano, Momirlan, and Bockris independently discussed the concept of a hydrogen fuel economy and storage methods. One of the key advantages of hydrogen is its environmental appeal, as it does not produce common pollutants or greenhouse gases when used as an energy carrier. However, despite its potential, the widespread adoption of hydrogen energy faces two significant challenges.