Screening of transition metal doped copper clusters for CO2 activation.

Activation of CO2 is the first step towards its reduction to more useful chemicals. Here we systematically investigate the CO2 activation mechanism on Cu3X (X is a first-row transition metal atom) using density functional theory computations. The CO2 adsorption energies and the activation mechanisms depend strongly on the selected dopant. The dopant electronegativity, the HOMO-LUMO gap and the overlap of the frontier molecular orbitals control the CO2 dissociation efficiency. Our calculations reveal that early transition metal-doped (Sc, Ti, V) clusters exhibit a high CO2 adsorption energy, a low activation barrier for its dissociation, and a facile regeneration of the clusters. Thus, early transition metal-doped copper clusters, particularly Cu3Sc, may be efficient catalysts for the carbon capture and utilization process.

Observation of the Reaction Intermediates of Methanol Dehydrogenation by Cationic Vanadium Clusters.

A mass spectrometric study of the reactions of vanadium cationic clusters with methanol in a low-pressure collision cell is reported. For comparison, the reaction of methanol with cobalt cationic clusters was studied. For vanadium, the main reaction products are fully dehydrogenated species, and partial dehydrogenation and non-dehydrogenation species are observed as minors, for which the relative intensities increase with cluster size and also at low cluster source temperature cooled by liquid nitrogen; no dehydrogenation products were observed for cobalt clusters. Quantum chemical calculations explored the reaction pathways and revealed that the fully dehydrogenation products of the reaction between Vn + and methanol are Vn (C)(O)+ , in which C and O are separated owing to the high oxophilicity of vanadium. The partial dehydrogenation and non-dehydrogenation species were verified to be reaction intermediates along the reaction pathway, and their most probable structures were proposed.