Selective Hydrogenation of CO₂ to CH₃OH on a Dynamically Magic Single-Cluster Catalyst: Cu₃/MoS₂/Ag(111)

Selective hydrogenation of carbon dioxide (CO₂) into value-added chemicals via highly efficient catalysts is of great significance in CO₂ conversion and utilization. Here, taking Cu_N/MoS₂/Ag(111) heterostructures (N = 1–8) as prototypical examples, we theoretically establish a concept of a dynamically magic single-cluster catalyst (DMSCC) for high-efficient selective hydrogenation of CO₂ to CH₃OH. It is found that, though Cu₂ and Cu₈ in the gas phase are well recognized as magic clusters due to closed-shell electronic structures, Cu₃ and Cu₇ become new magic clusters when deposited on MoS₂/Ag(111) due to their high-symmetric structures and strong Cu–S ionic bonding. Moreover, the dynamic evolution of the geometric structure of the Cu₃ species with an alkali-metal-like electronic feature and the d_z² frontier orbital accounts for its highly selective catalytic activity for CO₂ reduction to CH₃OH rather than HCOO with a low rate-limiting reaction barrier of ∼1.10 eV. However, the deposited Cu₇ is relatively highly inert toward CO₂ activation because of its halogen-element-like electronic characteristics. The present findings on DMSCC are expected to be constructive in design and fabrication of highly efficient single-atomic-scale catalysts for CO₂ activation and conversion.