Hydrogen fuel is probably most controversial alternative fuel. It is powerful and clean, but difficult in handling and storage. Although hydrogen is most abundant chemical element that can be produced everywhere, transformation in energy usable form is not economic viable. Water can be a great resource for production of combustible hydrogen, but electrolysis and other current technologies must be improved or changed by more efficient methods. Efficient mechanism of water splitting into hydrogen and oxygen would provide energy needs; minimize human contribution to global warming. There are plenteous scientific efforts to produce hydrogen fuel from water.

Water Decomposing by Radio Waves – Burning Salt Water

Scientists long have thought that water couldn't be burned. John Kanzius discovered water molecule decomposing and splitting into oxygen and hydrogen. He performed salt water burning, so spawned scientific interest in using the water as clean fuel. There are no electrodes. He developed radio frequency generator as a novel cancer treatment. Research was focused on cancer cells eliminating supposedly looking for resonant frequencies of the cells themselves, so hydrogen ignition and burning was accidentally due to water splitting into oxygen and hydrogen.
He put sea water in a test tube; heat from burning hydrogen grew hot enough to melt the test tube, producing an unexpected spark. Tests on different concentrations of sodium chlorate - water solutions produced various temperatures and flame colors. Kanzius proposed that the flame is produced by burning of hydrogen and oxygen, obtained from water molecule splitting by radio waves. Kanzius called it reunification process and said that "In this case we weren't looking for energy, we were looking for something that might do desalinization. The more we tried desalinization, the more heat we produced, until we got fire". Unfortunately, he passed away Feb. 19, 2009. No additional information about the project on John Kanzius’s official website and PesWiki webpage since that time.

Water Splitting by Smart Metal Complex

Researchers at the Weizmann Institute, Organic Chemistry Department have developed a new way of splitting water molecules that can separate oxygen from water and bind the atoms in a different molecule. Weizmann team has three important steps in water molecule splitting helped by ‘smart metal complex’. Basic element of that metal complex is ruthenium. The first step is water splitting into hydrogen and hydroxyl group. When water is mixed with this complex, covalent bond between the hydrogen and oxygen atoms breaks. Hydrogen atom binds with organic part of the complex, the hydroxyl group bind to its metal center. The second stage is known as heat stage. Here the water solution is heated up to boiling. This releases the hydrogen gas from the complex. Here comes our clean and green source of fuel. Another OH group is added to the metal center. Project leader, Professor Milstein explained third stage, “When we exposed this third complex to light at room temperature, not only was oxygen gas produced, but the metal complex also reverted back to its original state, which could be recycled for use in further reactions.” The team has discovered that during the third stage, light provides the energy for the two OH groups to get together to form hydrogen peroxide (H₂O₂). This hydrogen peroxide quickly breaks up into oxygen and water. Another interesting thing the team has spotted is that the bond between the two oxygen atoms is generated within a single molecule. This bond formation doesn’t occur between oxygen atoms located on separate molecules, but it comes from a single metal center.
The greatest achievement of Milstein’s team has been the development of a mechanism for the formation of hydrogen and oxygen from water, without the need for sacrificial chemical agents. It has been achieved by using individual steps and utilizing light. For their next project, they intend to combine these stages to create a proficient catalytic system.

Water Splitting by Aluminium Clusters

Researchers at Pennsylvania State University and Virginia Commonwealth University have developed the process of hydrogen production by exposing clusters of aluminum atoms to water. The process is based on the presence of Lewis acids and Lewis bases in those atoms. In the presence of the aluminum, the water acts as a Lewis base, interacting with the Lewis acids in the aluminum cluster. Lewis bases are chemical compounds, or molecules, that can donate a pair of electrons to Lewis acids, compounds, or molecules with two free slots in their highest occupied molecular orbital. Thus, water can donate hydroxyl groups to aluminum cluster acting as base. Then, hydrogen atoms become free, which join becoming hydrogen gas.
Shiv Khanna, Professor of Physics, explained that "Traditional techniques for splitting water to produce hydrogen generally require a lot of energy at the time the hydrogen is generated. But our method allows us to produce hydrogen without supplying heat, connecting to a battery, or adding electricity. Once the aluminum clusters are synthesized, they can generate hydrogen on demand without the need to store it."
The team discovered that the aluminum clusters react differently when exposed to water, depending on the sizes of the clusters and their unique geometric structures.

There are many other researches of hydrogen fuel production from other sources. It seems that scientific efforts are accelerated. We shall have huge benefits, if they reach the goal – commercial production of hydrogen fuel.

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