Interaction of a Co6 cluster with oxides of different nature: a quantum chemical study

Abstract

Density functional theory was applied to investigate the interaction of Co 6 nanoparticle with various oxide supports including γ Al 2 O 3 , silicalite, and zeolite HZSM 5. The introduc tion of cobalt into silicalite leads to insignificant stabilization of the metal cluster and induction of a small positive charge. The interaction of the Co 6 particle with the acid zeolite or alumina is accompanied by transfer of either a proton from the Brønsted acid site or hydrogen atoms from terminal OH groups to the surface of the metal cluster with the formation of a hydride like complex cation. Geometric parameters and energy characteristics of adsorption complexes of carbon monoxide molecule with Co 6 particles on different supports were calculated. For isolated particle on silicalite, "linear" adsorption is predicted. According to calculations, one can expect "angular" adsorption in the case of the acid zeolite and "two point" adsorption (precursor of active surface carbon) in the system Co 6 /γ Al 2 O 3 .