CO₂ and H₂ Activation on Zinc‐Doped Copper Clusters

Abstract

Here we systematically investigate the CO₂ and H₂ activation and dissociation on small Cu_nZn^0/+ (n=3–6) clusters using Density Functional Theory. We show that Cu₆Zn is a superatom, displaying an increased HOMO‐LUMO gap and is inert towards CO₂ or H₂ activation or dissociation. While other neutral clusters weakly activate CO₂, the cationic clusters preferentially bind the CO₂ in monodentate nonactivated way. Notably, Cu₄Zn allows for the dissociation of activated CO₂, whereas larger clusters destabilize all activated CO₂ binding modes. Conversely, H₂ dissociation is favored on all clusters examined, except for Cu₆Zn. Cu₃Zn⁺ and Cu₄Zn, favor the formation of formate through the H₂ dissociation pathway rather than CO₂ dissociation. These findings suggest the potential of these clusters as synthetic targets and underscore their significance in the realm of CO₂ hydrogenation.