Forget the ring, platinum has better uses in cars

New York (Jun 21)  Platinum is a rare and expensive metal, and one classed above gold. The metal has a more important use than jewelry; it is proving to be the most efficient catalyst for the power industry.

Based on a report by the U.S. Department of Energy's Office of Science, platinum is being used increasingly in chemical plants as a catalyst. A catalyst is something which speeds up or enhances reactions. Reactions that are faster, or where more of the desired effect is obtained, are more efficient.

A key application is with fuel cells. Here, minute platinum particles disassociate hydrogen fuel to create electricity, and the leftover chemicals combine to produce water. Although fuel cells are being used more often in power plants, because they are portable and lightweight they have other applications in terms of remote use. Examples include spacecraft and military vehicles. One of the ultimate goals is with cars, where fuel cells, in theory, could replace gasoline.

Two companies have produced such cars: the Toyota Mirai and the Hyundai ix35 FCEV, although these remain at the prototype stage. In trials, the Hyrundai FCEV has been driven for some 3,000,000 miles and it has been subjected to around 27,000 re-fueling sessions. With the Mirai (Japanese for "future"), Toyota will be producing over 700 vehicles during this year.

Another enticing application, is that fuel cells could allow wind to be transformed into fuel. Currently, electricity generated by wind turbines is not captured. If the energy can be converted into hydrogen to power fuel cells, this could lead to a continuous power source. This project is being examined at the U.S. the National Wind Technology Center (Boulder, Colorado).

The biggest limiting factor, the U.S. Department of Energy's Office of Science notes, is that availability of platinum. Platinum is what is classed as a rare metal. When used in catalysts, the metal is in the form ‘platinum black’, which is a black, fine powder.

Researchers are seeing whether artificial alternatives to platinum can be constructed. The key here is to understand how the metal moves protons. This is important for the chemical reaction, enhanced by the catalyst, to work in the case of fuel cells. Work so far, at the Pacific Northwest National Laboratory, has focused on using less platinum and combining it with nickel and to see if similar effects can be created. Initial studies on “hollow platinum and nickel nanoparticles, a thousand times smaller in diameter than a human hair” have been successful and further examinations are taking place.

Source: DigitalJournal