A highly stable and recyclable palladium nanocatalyst supported on a core-shell structure for Suzuki cross-coupling

This article introduces a palladium catalyst supported on a core-shell composite carrier with high stability and excellent recyclable, along with its application in Suzuki cross-couplings. By combining the high stability of silica with the charge effect of graphene oxide's laminar structure, nanosized graphene oxide (NGO)-coated aminated silica (AP-SiO 2 ) was utilized as a support material. An imidazole ligand (Lmd) was modified on the support surface to serve as a σ-donor for stabilizing and loading palladium nanoclusters, thereby designing a heterogeneous catalyst with a core-shell structure (AP-SiO 2 @NGO/Lmd-Pd). A series of analytical methods confirmed the core-shell structure of the catalyst, as well as the high dispersion of palladium nanoclusters on the support. The TGA curves demonstrated that the catalyst exhibited high thermal stability. The catalyst exhibited exceptional performance in catalyzing the Suzuki cross-couplings. It achieved a near 100 % yield within 20 min using only 0.5 mol% of the catalyst under optimal conditions. It also exhibited good universality in coupling reactions with diverse aryl halides and phenylboronic acid derivatives. Additionally, the catalyst maintained its activity even after being reused up to 10 cycles.