First-principles studies for CO and O2 on gold nanocluster

Abstract

First-principles calculations are performed to study the interaction of gold nanocluster Au55 with small molecules CO and O2. We find that the adsorption energy of CO on Au55 is among 0.5-0.7 eV at different sites and [CO+ O2] can be coadsorbed on Au55. Comparisons between Au55 and Au32 show that the adsorption energy not only depends on the size of the cluster but also on the geometry of the cluster. Similar with smaller cluster (Au8 and Au32), the energy difference between [CO+ O2] and [CO2 +O] on Au55 is much larger than that in the free gas. Our calculations indicate that the nanocluster Au55 can enhance the reaction process, CO+ O2 → CO2 +O, in which the reaction barrier is only about half electron volts. © 2010 American Institute of Physics.