Stabilizing Pd on magnetic phosphine-functionalized cellulose: DFT study and catalytic performance under deep eutectic solvent assisted conditions.

A highly efficient metal-based nanocatalyst was developed by stabilization of palladium nanoparticles on magnetically retrievable phosphine-functionalized cellulose (FeO@PFC-Pd(0)). The synthesized nanocatalyst was characterized by various techniques such as FT-IR, XRD, FE-SEM, TEM, EDX, UV-vis, ICP, TGA, BET and VSM. Moreover, to investigate the metal-ligand interactions present in the nanocatalyst, covalent and electrostatic interactions, density functional theory (DFT) and quantum theory of atoms in molecule (QTAIM) methods were employed. The catalytic efficacy of the nanoparticles was evaluated in Sonogashira and Suzuki coupling reactions in basic deep eutectic mixture, as a sustainable solvent. Due to the cooperative interactions of primary hydroxyl group of cellulose, phosphorus atom and phenyl ring of phosphine moiety with Pd atom, the nanocatalyst exhibits high activity and stability. The nanocatalyst can be easily recycled and reused at least five times without an appreciable loss of activity. Also, the other merits including short reaction times, short synthetic route to prepare catalyst, trace metal leaching to the reaction medium, cost-effective and eco-friendly conditions can be mentioned for the present approach.