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Tuesday, May 3, 2011

Iran- Big Step Towards Improving Quality of Fuel Cells http://english.farsnews.com/newstext.php?nn=9002134492

Iranian researchers at Sharif University of Technology successfully employed theoretical calculations to choose specific nano-metals which reduce oxygen consumption of fuel cells."A significant portion of performance loss in fuel cells is generally attributed to the voltage rise for oxygen reduction in cathodes. Also, those cells which run on conventional alcohols like methanol or ethanol suffer from alcohol permeation from anodic to cathodic section," Ramezan Arab, one of the researchers, said."Such a migration poisons the oxygen electrode and results in voltage loss and performance degradation of the mentioned fuel cells. Therefore, researchers have been after appropriate catalysts which simultaneously enhance oxygen reduction and resist poisoning by alcoholic compounds," he added. 

"Key parameters influencing the speed of oxygen redox reaction are rates of oxygen sorption and formation of intermediates such as peroxide (H2O2) and hydroxide (OH) upon the electrode surface. So, the theoretical studies on adsorption of such molecular types on electrode surface help provide insights into kinetics and mechanism of oxygen reduction process. This facilitates the selection of appropriate metals/alloys for practical uses," Arab noted.The results indicate that as negative charges of the nano clusters increase, the molecular/ atomic oxygen adsorption models as well as the most stable adsorptive status vary. It is also reported that the molecular/atomic oxygen adsorption energy decreases with copper content of the neutral nano clusters. However, the reverse holds true for negative charged nano clusters.

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