Manipulating the Active Sites in Single-Nanocluster Catalysis by Heterometallic Coordination Hybridization at Atomic...

Constructing accessible active sites on the surface of catalysts at the atomic precision remains challenging in heterogeneous single-nanocluster catalysis. Leveraging the differences in coordination preferences between various metals and ligands, a heterometallic coordination hybridization (HCH) protocol was proposed to manipulate the stable and accessible active sites on the surface of single-nanocluster catalysts. A homoleptic superatomic nanocluster [(AuCu)₇₁(m-MBT)₄₆](CF₃SO₃)₃ (short as (AuCu)₇₁ and m-MBT = 3-methylbenzenethiol) was synthesized in high yield, and its structure was determined by single-crystal X-ray diffraction. Benefiting from the HCH strategy, (AuCu)₇₁ features four open, accessible, and stable dual-Au sites on its surface. Notably, heterogeneous single-nanocluster catalyst (AuCu)₇₁/XC-72 (XC-72 is carbon support) exhibited excellent catalytic performance for denitrative C-O coupling under mild conditions (60 °C, atmosphere). The turnover numbers and turnover frequencies reached record high values of 2.88 × 10⁶ and 3.48 × 10⁵ h^-1, respectively, which are four orders of magnitude higher than those observed for the well-established Pd/C system. The remarkable catalytic performance of (AuCu)₇₁ was attributed to the exposed dual-Au sites, which facilitated the adsorption of deprotonated phenol and its derivatives via Au-O interactions, guided the proximity of nitroarenes rather than being commonly absorbed simultaneously on active sites, and exhibited exceptional durability of the catalyst. The HCH protocol provides new idea for the rational design and construction of heterogeneous metal catalysts with well-defined accessible active sites.