Pd Catalysts Supported on γ-Al2O3 Immobilized with Ionic Liquids: An Efficient and Recyclable System for C-C Bond Formation

A novel γ-Al ₂ O ₃ /IL-Pd catalyst has been designed and synthesized, featuring the highly dispersed deposition of active palladium nanoparticles on the surface of porous γ-Al ₂ O ₃ , which enhances catalytic performance and recyclability. The incorporation of ionic liquids is critical to the catalyst's design, as it facilitates the complete dispersion of active metals through chelation, effectively preventing the formation of palladium black and addressing catalyst deactivation. The interaction between the ionic liquid and the support, likely through specific coordination chemistries, significantly enhances the recovery and reuse capabilities of the catalyst by preventing the leaching and sintering of the palladium nanoparticles. This approach not only resolves the agglomeration issue inherent to γ-Al ₂ O ₃ but also optimizes the catalyst's performance further. In the Suzuki-Miyaura coupling reaction, the new catalyst demonstrates remarkable catalytic activity, achieving a yield of tetramethoxybiphenyl of up to 99% within a remarkably short reaction time of just 30 minutes, without the need for inert gas protection. Notably, after ten consecutive cycles, the catalyst's performance remained at 94%, outperforming many existing catalysts and confirming its exceptional stability and recyclability. Given its high efficiency, stability, and reusability, this catalyst is positioned to serve as a high-performance multifunctional catalytic platform for a range of significant organic synthesis reactions.