Not only one time had ethanol been tested as a reliable source of hydrogen. Now, a multi-national team of scientists from Spain, Scotland and New Zealand have devised a method to use ethanol and sunlight to extract hydrogen for use in fuel cells to generate electricity.
The process the researchers invented takes place at ambient temperature and is generally simpler and cheaper than that used in splitting water. Basically, a solid photocatalyst is placed in an ethanol solution and exposed to ultraviolet light, the most energetic part of the light spectrum. The solution also contains titanium dioxide, a semiconductor that’s already being used in organic solar cells as the substance in charge with generating electrons when hit by photons.
The electrons thus produced are captured by metallic gold nanoparticles, 2 to 12 nanometers in size, which in turn react with the ethanol molecules and produce hydrogen. The researchers found out that the size of these particles is not important, as it is in water-splitting approaches.
During their experiments, the researchers have used one kilogram of catalyst to generate up to 5 liters of hydrogen per minute. 9 kg of catalyst were able to generate enough hydrogen to make a fuel cell generate 3 kW of electricity, which is fairly the amount used in a regular household.
As good as it may sound, this method of producing hydrogen has its drawback. The trade-off is that ethanol also emits carbon dioxide and is only available in its clean form from quickly-growing biomass, while water is all around us. It is nevertheless precious as a scientific model to follow and could even produce electricity successfully in several applications such as electric fuel cell vehicles. In that case, the infrastructure carrying fossil fuels could easily carry ethanol and the transition to electric cars would be way easier.
