ACADEMIA

Splitting oxygen molecules into oxygen atoms and the subsequent formation of water are currently the rate limiting step in getting energy from fuel cells, the reaction that restricts overall power production. According to the University of Wisconsin at Madison's Manos Mavrikakis, this oxygen reduction reaction, as it's known, is responsible for about 60 percent of common fuel cell designs' overall efficiency loss. Until this part of the process becomes more efficient, low-temperature fuel cells will not be commercially viable. Mavrikakis, his collaborators at Wisconsin, and a group of experimental chemists at Brookhaven National Laboratory (led by Radoslav Adzic) are exploring the oxygen reduction reaction and the catalyst that provokes it. Namely, they're looking to make the reaction more efficient and to reduce the cost of expensive all-platinum catalysts. In 2005, articles by the team in the Journal of the American Chemical Society and Angewandte Chemie, International Edition showed the value of what are called platinum-monolayer catalysts. The bulk of these catalysts are a cheaper material with a layer of platinum that is a single atom thick covering them. The team compared a variety of catalysts. Ultimately they found that palladium with the platinum monolayer, which is markedly cheaper, offered the best overall performance characteristics. It improved the overall efficiency of the oxygen reduction reaction by 33 percent. The team uses NCSA Tungsten and computing resources at the Department of Energy. Currently, the teams' calculations focus on other competitive reaction paths for the oxygen reduction reaction. In the future, they hope to add already-formed water molecules, develop the reactivity trends, and explore how those molecules might influence the oxygen reduction reaction as well.