Heteronuclear Neighboring Co-Mn Single-Atom Pairs as a Synergistic Platform for Oxidative C-H Functionalization.

The transition from conventional single-atom catalysts to heteronuclear neighboring single-atom catalysts presents a compelling strategy to address the limitations associated with isolated metal sites in multielectron oxidative transformations. Herein, we report a Co-Mn heteronuclear single‑atom catalyst (Co1-Mn1/NC) in which atomically dispersed Co and Mn species are anchored on a nitrogen‑doped carbon support to form well‑defined neighboring active pairs with an interatomic distance of ∼2.6 Å. This configuration provides a synergistic platform that markedly outperforms its monometallic Co and Mn counterparts in two challenging oxidative C-H functionalization reactions: the selective oxidation of acenaphthene to 1‑acenaphthenol (99.9% conversion, 97.7% selectivity) and the oxidative condensation of benzyl alcohol with methanol to benzaldehyde dimethyl acetal (63.4% conversion, 94.7% selectivity). Atomic‑resolution characterization and DFT calculations elucidate the origin of this synergy, revealing a division of labor between the two metal centers. In acenaphthene oxidation, the Co-Mn pair cooperatively activates molecular oxygen and facilitates C-H bond dissociation with a substantially reduced energy barrier. In the oxidative condensation, the Co site preferentially activates methanol while the adjacent Mn site stabilizes the key *PhCHO intermediate. This work establishes heteronuclear neighboring Co-Mn pairs as a platform for synergistic multifunctional catalysis.