Nanomaterial synthesis by spark discharge with application in hydrogen technologies

February 2020

Just as electric cars are replacing fossil fuel cars today, in the future electric cars will be replaced by hydrogen cars. Technologies are already being developed to manage this transition – one of them in the research programme Efficient Energy Conversion and Storage of Strategy AV21, the strategic initiative of the Czech Academy of Sciences.

Hydrogen fuel cells are devices that convert the chemical energy of hydrogen into electricity. In contrast, electrolysers break down water into hydrogen and oxygen. Thus, hydrogen can be obtained as fuel for fuel cells. Both these devices are expected to be widely used in the hydrogen economy in the future, where fuel cells will be a source of energy for cars, but also for hospitals or even for small electronic devices. Before this happens, scientists are bracing for a race to ensure the highest efficiency and lowest cost of these technologies.

Fuel cells and electrolytic cells of the PEM type (with a polymer electrolytic membrane) are among the most promising. An important factor affecting their efficiency and cost is the catalytic layer. This is most often made up of platinum nanoparticles or its alloys deposited on a polymer membrane.

Our patented technology uses a high spark discharge temperature to vaporize the metal. The metal fumes are cooled by a gas stream and condensed to nanometer-sized particles. At the same time, the gas stream carries the formed particles onto the functional layer. The currently used methods of nanoparticle preparation require vacuum and lengthy batch chemical preparation by wet process. On the other hand, the new method does not require a vacuum, and by very fast repetition of the spark discharge, it enables the continuous production of nanoparticles, which can moreover be easily formed from more than one metal. The very small particle size makes it possible to reduce the amount of precious metal used while maintaining the necessary properties, which reduces costs.

Platinum nanoparcitles as observed by electron microscope

Scientists at the Taiwanese Industrial Technology Research Institute (ITRI) have shown interest in our patented technology in 2019, testing its effectiveness against alternative technologies. Although further research is ahead to increase the efficiency of the method, the first results are promising.

Contact: Dr. Tomáš Němec, Institute of Thermomechanics of the CAS