Hydrogen is often proposed as the fuel of the future, but the transformation from the present fossil fuel economy to a hydrogen economy will need the solution of numerous complex scientific and technological issues.

Nicola Armaroli and Vincenzo Balzani have reviewed the use of hydrogen in several different technologies and examined their feasibility. They predict that the development of a hydrogen economy, in the short term, will most likely rely on water electrolysis as:

• the production of hydrogen from hydrogen-rich compounds such as gasoline or natural gas offers no advantage over the direct use of such fuels
• generation from water splitting with methods such as artificial photosynthesis are still far from being practical.

Armaroli and Balzani conclude that hydrogen technologies will play an essential role in phasing out fossil fuels, but this depends on the development of renewable energy sources on a large scale before hydrogen can truly be considered a ‘green’ fuel.

• The Hydrogen Issue
  N. Armaroli, V. Balzani,
  ChemSusChem, 2011.
  DOI: 10.1002/cssc.201000182