科研之友
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摘要
The dependence of the kinetics of electrocatalytic oxygen reduction in basic electrolyte on the size of Au nanoparticles was determined for 3 and 7 nm clusters supported on carbon. The size-selected nanoparticles were prepared by reverse micelle encapsulation using PS-P2VP diblock copolymer, and the kinetic current for oxygen reduction was measured with a rotating disk electrode (RDE). The kinetic current was found to be 2.5 times higher for the 3 nm gold nanoparticles compared to the 7 nm gold nanoparticles at 23 degrees C. The 3 nm particles were found to facilitate four-electron electroreduction, whereas a two-electron electroreduction was inferred from the RDE data on the 7 nm particles. From experiments of the temperature-dependent current the apparent activation energy for the 3 nm clusters was found to be half that of the 7 nm clusters (0.1 and 0.2 eV, respectively).
- 出版日期2008-7-17
