Bismuth Nanoparticles Supported on Biobased Chitosan as Sustainable Catalysts for the Selective Hydrogenation of Nitroarenes

The use of chitosan as a support in the field of catalysis has gained tremendous interest because of its abundance and sustainability. We herein disclose a straightforward strategy to trap and stabilize bismuth nanoparticles (BiNPs) on chitosan biopolymer Bi@CS and their use for catalytic applications. Bi@CS was configured as micrometer-thick films, porous beads, and native powders analyzed and next used for the controlled and selective reduction of nitroaromatic compounds to their corresponding anilines and azoarenes, respectively, by varying the concentration medium in reducing NaBH4. A regioselective mechanism has been suggested. Powder nanocomposites CSp-BiNPs exhibited high catalytic capacity, and 10 corresponding anilines and 15 azoarenes were obtained with very high yields. The reductions were achieved under mild and sustainable reaction conditions (water solvent and room temperature) with easy processing and 12 recovery cycles. Shaped catalysts were easily recovered by simple filtration. This catalyst, derived from nontoxic and affordable bismuth metal supported on chitosan ocean waste, presents significant improvements in the realm of sustainable chemistry and could open a new channel of possibilities for green catalysis.

Automated summary

In this study, a straightforward strategy is demonstrated to trap and stabilize bismuth nanoparticles on chitosan biopolymer for catalytic applications. The resulting catalyst showed high catalytic capacity and selectivity in the reduction of nitroaromatic compounds, leading to the production of anilines and azoarenes with high yields under mild and sustainable reaction conditions.