Development and Characterization of a High-Performance Ligand-Free Palladium Catalyst Supported on Cellulose Spheres

Abstract

An efficient method has been developed for preparing heterogeneous palladium catalysts embedded within cellulose spheres, which involves either direct droplet deposition or utilization of an electrospinning technique. The metallic palladium nanoparticles, with an average diameter of 6.39 ± 4.71 nm, were uniformly incorporated into the cellulose spherical matrix. The direct droplet deposition method yielded cellulose spheres with an average diameter of approximately 2.0 mm, whereas those prepared using the electrospinning technique exhibited an average diameter of about 1.0 mm. Intriguingly, the prepared cellulose spheres demonstrated excellent catalytic performance in Suzuki cross-coupling reactions. This phenomenon could be attributed to the predominant distribution of the active Pd⁰ nanoparticles in the outer layer of the cellulose spheres. Significantly, the embedment of active Pd⁰ species greatly enhanced their reusability, as they retained high catalytic activity even after more than 10 cycles. In conclusion, this study presents a straightforward and efficient method for preparing highly active cellulose spheres–supported palladium catalysts, thereby expanding the potential applications of cellulose-based biopolymeric materials.