Plasma‐Assisted Dinitrogen Activation on Small Cobalt Clusters: Co₄N₉⁺ with Enhanced Stability

Abstract

We have performed a study on the accommodation of nitrogen doping toward superatomic states of transition metal clusters. By reacting cobalt clusters with N2 in the presence of plasma radiation, a large number of odd‐nitrogen clusters were observed, typically Co3N2m‐1+ (m=1–5) and Co4N2m‐1+ (m=1–6) series, showing N≡N bond cleavage in the mild plasma atmosphere. Interestingly, the Co3N7+, Co4N9+, and Co5N9+ clusters exhibit prominent mass abundances. First‐principles calculation results elucidate the stability of the diverse cobalt nitride clusters and find unique stability of Co4N9+ with a swallow‐kite structure of which four coordinated N2 molecules causes a significantly enlarged HOMO‐LUMO gap, while the single N atom doping gives rise to superatomic states of 1S21P3||1D0. We reveal an efficient dinitrogen activation strategy by reacting multiple N2 molecules with cobalt clusters under a plasma atmosphere.

Graphene-Supported Single-Atom Ni as High-Performance Catalyst for Direct Methane-to-Methanol Conversion

“…The above conclusion is consistent with previous gas-phase studies of MO + catalyzing CH 4 to CH 3 OH that M = Ni affords the best reactivity and selectivity among M = Ni, Pd, and Pt. − This inspiring agreement indicates that gas-phase studies on simple molecules/ions are powerful to predict the catalytic behavior of heterogeneous catalysts that bear the same functional units. − …”

Magnetic Metal Clusters and Superatoms

“…It was found that Co 4 + possesses a relative higher reactivity to form a highly stable complex Co 4 N 9 + which has a Co 4 N core coordinated with four N 2 ligand molecules (Figure b). The superatomic frontier orbital features of Co 4 N 9 + show a swallow-kite structure with superatomic states (1S 2 1P 3 ||1D 0 ) mimicking an arsenic atom (4s 2 4p 3 ||4d 0 ) . These studies not only embody the previously proposed concept of special and general superatoms but also enlighten the rational design of magnetic materials and spin catalysts.…”

“…The superatomic frontier orbital features of Co 4 N 9 + show a swallow-kite structure with superatomic states (1S 2 1P 3 ||1D 0 ) mimicking an arsenic atom (4s 2 4p 3 ||4d 0 ). 28 These studies not only embody the previously proposed concept of special and general superatoms 5 but also enlighten the rational design of magnetic materials and spin catalysts.…”