A RhTaC2− cluster can reduce four CO2 molecules consecutively. The pivotal roles of Rh–Ta synergy and the C2 ligand in driving CO2 reduction were rationalized. A fundamental strategy to alleviate carbon deposition in the CO2 atmosphere was provided.

The key to optimize the energy-consuming catalytic conversions lies in getting a fundamental understanding on the nature of the active sites and the mechanisms of elementary steps at the atomically...

A fundamental understanding of the reactivity evolution of nanosized clusters at an atomically precise level is pivotal to assemble desired materials with promising candidates. Benefiting from the tandem mass spectrometer coupled with a high-temperature ion-trap reactor, the reactions of mass-selected Co n – (n = 5–25) clusters with CO2 were investigated and the increased reactivity of Co20–25 – was newly discovered herein. This finding marks an important step to understand property evolution of subnanometer metal clusters (Co25 –, ∼0.8 nm) atom-by-atom. The reasons behind the increased reactivity of Co20–25 – were proposed by analyzing the reactions of smaller Co6–8 – clusters that exhibit significantly different reactivity toward CO2, in which a lower electron affinity of Co n contributes to the capture of CO2 while the flexibility of Co n – could play vital roles to stabilize reaction intermediates and suppress the barriers of O–CO rupture and CO desorption.