Pd₁Au_l/Graphene: Highly Efficient Bimetallic Single-Atom Catalysts for C-C Coupling from C-B Bond Activation

Bimetallic single-atom catalysts (SACs) represent an emerging paradigm beyond single-atom catalysts for enabling synergistic catalysis. The homocoupling of arylboronic acids via C-B bond activation to form C-C bonds has been demonstrated to be entirely inert with Pd or Au SACs. This study achieves a breakthrough by developing a bimetallic single-atom catalyst (Pd₁Au₁/graphene), which delivers outstanding performance with a TON up to 19,192 and cycling stability (>90% yield after seven cycles). Through comprehensive experiments and theoretical calculations, we have identified a structure of PdN₄-AuN₄/graphene, where adjacent Pd and Au atoms form a synergistic active center. This promotes simultaneous aromatic boronic acid substrate activation and significantly reduces the reaction energy barrier of the oxidative addition step, thereby enabling a pathway inaccessible to isolated single atoms. This work not only provides an efficient catalyst for organic synthesis but also validates the fundamental principle of synergistic catalysis in bimetallic single-atom catalysts, offering a universal design strategy for addressing challenging transformations.