Platinum is expensive and one of the serious obstacles to the large-scale application of hydrogen fuel cells, one of the energy sources of electric vehicles, because hydrogen fuel cells require platinum. However, a research team led by Bruce E. Koel, a professor at the Department of Biological and Chemical Engineering at Princeton University, has succeeded in finding a cheaper alternative to platinum. The researchers said that they found a hafnium-based compound that works about 60% of platinum, but costs only about one-fifth that of platinum.
Fuel cells work by converting the energy stored in hydrogen atoms directly into electricity. NASA has long used fuel cells to power satellites and other space missions, and is now also used in electric cars and buses. Hydrogen is the simplest and most abundant element in the planet and the universe.
At its most basic, fuel cells generate electricity by splitting hydrogen into protons and electrons. Protons flow through the membrane and combine with oxygen to form water. The negatively charged electrons flow to the positively charged electrodes in the fuel cell. The flow of electrons is the current generated by the fuel cell and can provide power to the engine or other electronic devices. And other materials as a catalyst.
Catalysts are also used on hydrogen fueled fuel cells to produce hydrogen. In the most ideal case without fossil fuels, renewable electrical energy can split water molecules (two hydrogen atoms and one oxygen atom) with the help of a catalyst to split water into oxygen and hydrogen, and the higher the efficiency of the catalyst, the more decomposition The less energy the water needs.
Some advanced fuel cells, namely regenerable fuel cells, combine the two reactions described above. However, most fuel cells currently rely on hydrogen produced by independent systems to become hydrogen fuel cells. However, currently the best catalysts for both reactions are platinum group noble metals. Researchers believe that platinum is perfect. Platinum group precious metals can quickly and efficiently catalyze chemical reactions to extract hydrogen, and such metals can withstand the harsh acidic conditions required for such reactions.
However, the problem is that platinum is scarce and expensive. However, researchers think that hydrogen, a fuel cell for electric vehicles and the like, does not require platinum as a perfect material. Researchers have found that hafnium hydroxide is a good alternative that uses nitrogen plasma (a plasma is an ionized gas that can be found in fluorescent lamps and the state of matter in the sun) to process nitrogen atoms into the material.
Previously, many materials were ignored because they were not conductive. However, researchers have found that treating ytterbium oxide with a nitrogen plasma forms a thin film material that acts as a highly active catalyst and can survive strong acid conditions. Although the efficiency of this hafnium-based film is only about two-thirds of platinum, the price is much cheaper. Researchers plan to test zirconium next because zirconium is cheaper.
Although this material is well-suited for use in fuel cells, researchers believe it is most valuable in systems that use catalysts to electrochemically split water to produce hydrogen as a fuel. And researchers emphasize that the discovery will not enable the commercialization of inexpensive new technologies in the near future. Currently, the process of making this material is very complex and limited to laboratories. Although they have determined the properties of such films, they still need to consider the engineering techniques required for mass production of such materials. However, the study opens the door for further exploration of alternatives to platinum.