Theoretical study of molecular nitrogen adsorption on Au clusters

The adsorption properties of nitrogen molecule on anionic, cationic, and neutral Aun clusters (n=1-6) are studied using the density functional theory with the generalized gradient approximation, and with the hybrid functional. Our results show that cationic and some of the neutral Au clusters (n=2-4) can adsorb N2 molecule, and anionic clusters cannot. The adsorption energies of N2 on those Au clusters are around 0.2-0.9 eV at B3LYP level, which indicates that the adsorption may affect the catalytic activity of Au clusters in NO catalytic reductions at low temperature. The adsorption of N2 on Au clusters can be characterized by the frequencies of Au-N vibrations which are around 200-300 cm−1.