Getting Hydrogen from water // EIT Digital

Getting Hydrogen from water

Unlike conventional water splitters, the Stanford device uses a single low-cost catalyst to generate hydrogen on one electrode and oxygen on the other. Credit: L.A. Cicero/Stanford University

H2O is probably one of the most known chemical formula: any molecule of water consists of 2 atoms of Hydrogen (H) and one atom of Oxygen (O). And there is no shortage of water (yes many Countries have shortage of sweet and drinkable water but water in general is abundant, plenty of it in the seas and oceans). 

Hydrogen is a very good fuel, it has a high energy density and when it "burns" transforming chemical energy in thermal energy it produces water (it combines with O). Hence a perfect fuel that does not pollute.

The problem is that most of the H produced today is obtained from hydrocarbons, oli and gas, and the process of production generates plenty of pollutant. So your H-car is clean but the dirty stuff (pollutants) had already been dispersed in the environment.

Extracting H from water is expensive. The splitting of the molecule occurs when an electrical current flows in the water. The amount of production (speed of splitting) depends on the type (and shape) of the electrodes - best ones are made in platinum and iridium- and on the catalysts used. The most efficient splitters use two catalysts that have to be separated by a barrier. All of these, catalysts, electrodes and barriers make for a quite expensive package.

Here is where this news coming from Stanford is potentially changing the landscape: researchers at Stanford have managed to obtain an efficient splitting using only one catalyst, thus getting rid of the need of a barrier.

You can watch the clip and read the news for the details. It is indeed an important progress since whatever provides cheap- affordable products/innovations is a potential winner.

Be careful, however. Even if you have the ocean in front of your home the production of H won't come free. The H sits well with O, the molecule is stable, and to split it you need to provide energy. Actually, in the transformation from H2O to H and O and then on in the transformation from H and O to H2O you are "losing" some power, i.e. some of the energy gets lost in heat. It is not a "free lunch".

The interest in splitting water to produce H, hence, is not in creating low cost fuel, but in creating a fuel that is more convenient to use. Think about having solar panels. They produce electrical current when the Sun is up, but when the Sun is not shining you cannot have any power out of them. On the contrary, H can be stored, cheaply, and can be tapped on demand, when you need power.

The plan is to use any excess of power on the grid that could not be sold to the market to produce H. If you are using power that has very low value ('cause there is no market demand) you can dismiss this part of the cost. But the cost of the "machine" that produce the H needs to be small, and this is what the Stanford research promises to do.

Author - Roberto Saracco

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