Today is the day that the Livermore Laboratory in the USA prepares an ad extraordinary on nuclear fusion, but I recommend caution and still a lot of patience. We'll talk about it when it's done, we don't want to chase rumors (at least on the topic).
There is so much to say about already official discoveries! For example, researchers at RMIT announce that they have unlocked a production of green hydrogen cheaper and more energy efficient with a new electrolysis technique enhanced by sound waves.
With these high-frequency sound waves active, standard electrolysis produces green hydrogen 14 times easier and faster. Not bad, eh, waiting for the "infinite" energy.
The long march
Green hydrogen is trying (with some difficulty, it must be said) to become an important point of reference among zero-emission fuels. Among its strengths is the fact that it can “carry” a greater density of electrons and support rapid replenishment.
Green hydrogen, as you know, is created through electrolysis: splitting water molecules into hydrogen and oxygen using renewable energy to attract each gas to a different electrode, where the hydrogen can be captured, compressed and stored.
Why does this process work so much better when exposed to high frequency (10 MHz) sound waves?
There are at least three reasons, according to a research paper just published in the journal Advanced Energy Materials (I link it here).
First: the vibration of the water subjected to high frequency sound waves has the effect of "whipping" the water molecules closest to the electrodes, shaking them from the tetrahedral networks in which they tend to settle. This translates into more “free” water molecules that can better come into contact with the electrodes.
Second, since the separated gases collect in the form of bubbles on each electrode, the vibrations release the bubbles which "block" the contact of the electrode with the rest of the water and limit the reaction.
Third, high-frequency sound waves also help by generating hydronium (positively charged water ions) and creating convection currents that help with mass transfer.
The study of sound waves and green hydrogen
In their experiments, the research team chose to use electrodes that typically perform quite poorly. By opting for gold electrodes, which are relatively cheaper, he "snubbed" those generally used (platinum or iridium, rare and expensive). The electrolyte was also more "low profile", with a neutral pH, while they are usually strongly acidic or basic to improve the reaction speed.
No problem: that was what the scientists wanted to prove. When the team activated the high-frequency sound waves, the current density and reaction speed increased by a remarkable factor of 14.
Mind you: it's not a situation where, for a given amount of energy put into an electrolyzer, you get 14 times more hydrogen. It's a situation where water is split into hydrogen and oxygen 14 times more quickly and easily. And it still has an impressive effect on overall efficiency.
How much, exactly?
“With our high-frequency sound wave method we can improve the conversion efficiency leading to a net energy saving of 27%.” The professor says it Leslie Yeo, one of the principal investigators.
In summary? Faster reactions, energy savings and low-cost materials and electrolytes. Three crucial factors that will help reduce the price of green hydrogen.
The long march continues.
