Hydrogen is an ideal solution for cars of the future. The problem remains storage. People have a range they want to go (300 miles) before an automobile enhancement can become commercially acceptable. With hydrogen, that means carrying a tank the size of the car itself or compressing the hydrogen, which has unacceptable safety risks.
Dutch-sponsored researcher Robin Gremaud has shown that an alloy of the metals magnesium, titanium and nickel is excellent at absorbing hydrogen. A hydrogen 'tank' using this alloy would have a relative weight that is sixty percent less than a battery pack. In order to find the best alloy Gremaud developed a method which enabled simultaneous testing of thousands of samples of different metals for their capacity to absorb hydrogen.
The battery, the competing form of storage for electrical energy, comes off even worse than hydrogen today. Driving 250 miles with an electric car, such as a Toyota Prius, would require the car to carry 700 pounds of modern lithium batteries for its journey. With Gremaud's light metal alloy this same distance would require a hydrogen tank of 'only' 400 pounds.
Okay, not all that great either but still better than 700. Hydrogen storage is a way off but science is making progress.
Hydrogenography
In his research Gremaud made use of a technique for measuring the absorbance of hydrogen by metals, based on the phenomenon of 'switchable mirrors' discovered at the VU University Amsterdam. About ten years ago researchers at the VU discovered that certain materials lose their reflection by absorbing hydrogen. This technique became known as hydrogenography, or 'writing with hydrogen'. Using this technique, Gremaud was able to simultaneously analyse the efficacy of thousands of different combinations of the metals magnesium, titanium and nickel. Traditional methods require separate testing for each alloy.
The analysis requires each of the three metals to be eroded from an individual source and deposited onto a transparent film in a thin layer of 100 nanometres using so-called sputtering deposition. This ensures that the three metals are deposited onto the film in many different ratios. When the film is exposed to different amounts of hydrogen, it is clearly visible, even to the naked eye, which composition of metals is best at absorbing hydrogen.
Gremaud is the first to use this method for measuring hydrogen absorption. The British company Ilika in Southampton wants to build a hydrogen analyser using this technique.
