Electronic structure and reactivity indexes of cobalt clusters, both pure and mixed with NO and N2O (Conq, q=0, 1 and n=4-9)

Among the most popular motivations for environmental scientists is improving materials that could be useful to fight or avoid pollution. This work shows a study of neutral and cationic cobalt clusters from 4 to 9 atoms (Co-n(q), q = 0,1 and n = 4-9) to model their separate interaction with contaminant nitric and nitrous oxides. This study is within the framework of the density functional theory in the Kohn-Sham scheme by using BPW91 functional and 6-311G and 6-31G* basis sets to calculate global and local reactivity indexes. The effect of spin multiplicity is also determined. Results on the geometries of pure cobalt clusters agree with previously reported structures. Global minimum energy structures showed a marked preference towards the interaction of nitric and nitrous oxide molecules with cobalt clusters through chemisorptive dissociation, with the dissociation of the corresponding nitrogen oxide. Reactivity indexes reveal an even-odd alternate, which is related to electron counts. Moreover, the chemical potential is lowering after interaction with nitrogen oxides. The Fukui function illustrates the reactive zones with a high probability of chemisorption of more nitrogen oxide molecules.