Platinum May Need Replacing as a CatalystCategory: Science & Technology
Posted: July 17, 2012 07:27AM
For a long time platinum has been used as a catalyst for a variety of reactions. This is because it works for these different reactions and works reasonably well, but researchers have been looking for a replacement to the metal because of how expensive it is. Now researchers at Case Western Reserve University are suggesting that platinum needs to be replaced not just to bring down costs, but because it is holding back the efficiency of reactions.
Traditionally researchers have believed the reason platinum catalysts have not achieved the maximum theoretical efficiency is because of impurities on their surfaces. The Case researchers call this surface-poisoning explanation "lame" and describe it as a result of improperly using a statistical tool for comparing catalysts. When they did their own tests with platinum at the cathode of a fuel cell, the researchers found it was producing only 0.93 V instead of the theoretical maximum 1.23 V.
Though the researchers' analysis of platinum has been published in Physical Chemistry Chemical Physics and in Electrocatalysis, they can offer no better catalyst at this time. Copper laccase, a catalyst found in trees and fungi, should be able to produce more voltage according to the researchers' work, but is unstable, which makes it unusable as a catalyst at this time. Hopefully something with the performance of copper laccase and stability of platinum can be found.