Highly catalytically active composite of palladium nanoparticles covalently bound to chitosan nanofibers via dialdehyde cellulose.

This study introduces a novel, sustainable method for synthesizing sub-5 nm palladium nanoparticles (PdNPs) and covalently binding them to chitosan nanofibers (CHITs) using fully oxidized dialdehyde cellulose (DAC). Notably, the DAC acts not only as a reducing and stabilizing agent for PdNPs, but also as a linker for their rapid and spontaneous covalent attachment to CHITs via Schiff base chemistry. This unique approach yields PdNPs with a narrow size distribution (4.7 ± 0.4 nm) and enables the preparation of a stable nanofibrous composite with excellent catalytic efficiency for 4-nitrophenol reduction (TOF = 75.2 min, k = 1.34 min; TOF = 1.18 min). The composite's high reusability, attributed to strong covalent binding, marks a significant improvement over traditional PdNPs composites that rely on weak interactions. This is demonstrated on a model of a catalytic device, reflecting industrial applications.