Electrosprayed Cellulose Microsphere‐Supported Palladium Catalyst: A Sustainable and Reusable Catalytic System for the Heck Reaction

ABSTRACT

As the most abundant renewable biopolymer, cellulose exhibits great potential for the high‐value utilization of agricultural and forestry resources. Herein, palladium‐incorporated cellulose microspheres (Pd@MicroCell) were successfully fabricated via a facile one‐step electrospraying strategy, in which Pd ²⁺ /cellulose solution was directly sprayed into an aqueous reducing bath containing sodium borohydride (NaBH ₄ ). Palladium ions were in situ reduced to metallic Pd ⁰ nanoparticles and uniformly embedded within the regenerated cellulose matrix simultaneously. The resulting Pd@MicroCell microspheres were systematically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). The catalyst exhibited exceptional activity toward the Mizoroki‐Heck reaction of various aryl iodides and bromides with acrylates, affording consistent yields above 90% for most aryl iodides. Notably, it could be readily recovered by simple filtration and reused for at least 12 consecutive cycles without significant loss of catalytic activity. Inductively coupled plasma‐atomic emission spectroscopy (ICP‐AES) results demonstrated that the cumulative Pd leaching was ~27% after 12 cycles. The combination of renewable feedstock, facile synthesis, high efficiency, excellent stability, and reusability renders Pd@MicroCell microspheres a highly promising and environmentally benign heterogeneous catalytic system for sustainable chemical synthesis and industrial catalytic applications.