Theoretical study of molecular nitrogen adsorption on Wn clusters

The adsorption properties of N-2 molecules on anionic, cationic, and neutral W-n clusters (n = 1 - 5) are studied using the density functional theory with the generalized gradient approximation and with the hybrid functional. Adsorption energies accompanying charge population and vibrational analysis are used to characterize the adsorption properties of N-2 on W-n clusters with different sizes and charge states. Our calculations show that all the W clusters can adsorb one N-2 molecule with adsorption energy about 0.29-1.72 eV at B3LYP level, and 0.35-2.05 eV at PW91 level, by forming a linear or quasi-linear structure W-N-N. (c) 2008 Elsevier B.V. All rights reserved.