Synthesis of Novel Nanocellulose Aerogel Supported Pd Complex: Green and Efficient Catalyst for Heck Coupling Reaction

摘要

Natural polymers, especially polysaccharides, are explored for application in heterogeneous catalysis as immobilization support for metallic or organometallic catalysts. In this work, we designed a green Pd(0) based supported catalyst for Heck C-C coupling reactions. The support was produced from Nanofibrillated Cellulose (NFC) extracted from the rachis of date palm tree. The NFC was prepared by mechanical and chemical pretreatment by mean of TEMPO oxidation of the palm tree cellulose pulp. The Pd(0)-supNFC catalyst was characterized by mean of FTIR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and elementary analysis (EDX), and tested on Heck cross-coupling reaction in comparison with Pd(OAc)_2 with the same reaction under homogeneous conditions. Notable properties were found: eco-friendly processing, good reaction yields, very short reaction times, easy separation and reusability with insignificant loss of catalytic activity. More precisely the catalytic tests showed that the Pd(0)-supNFC catalyst has an excellent reactivity with a high reaction yield (90%) with low catalyst loading and short time reaction. In addition, the catalyst retained its activity even after three cycles.