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

Abstract

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.

Facile Transfer Hydrogenation of N-Heteroarenes and Nitroarenes Using Magnetically Recoverable Pd@SPIONs Catalyst

“…In this context, catalytic transfer hydrogenation (CTH) procedure is a safer, cleaner, and more efficient process for reducing a series of unsaturated compounds that can be reduced using sacrificial hydrogen donors, such as formic acid (HCOOH), hydrazine hydrate (NH 2 NH 2 ·H 2 O), ammonia borane (NH 3 ·BH 3 ), and sodium borohydride (NaBH 4 ). , In line with this effort, numerous catalytic systems have been developed, and most of the CTH systems have shown excellent results. For example, El kadiri et al demonstrated that bismuth nanoparticles (BiNPs) supported the chitosan biopolymer (Bi@CS) catalyst for the selective and controlled reduction of nitroaromatic compounds to anilines and azoarenes using NaBH 4 in water . Recently, Zhou et al reported the catalytic transfer hydrogenation of nitro compounds into amines over graphene oxide-supported Pd nanoparticles …”

“…For example, El kadiri et al demonstrated that bismuth nanoparticles (BiNPs) supported the chitosan biopolymer (Bi@CS) catalyst for the selective and controlled reduction of nitroaromatic compounds to anilines and azoarenes using NaBH 4 in water. 25 Recently, Zhou et al reported the catalytic transfer hydrogenation of nitro compounds into amines over graphene oxide-supported Pd nanoparticles. 26 Judicious choice of support plays a crucial role in affecting the metal−support interaction, which leads to substantial changes in the activity and selectivity of the catalyst.…”

3D Porous MoS2-Decorated Reduced Graphene Oxide Aerogel as a Heterogeneous Catalyst for Reductive Transformation Reactions

“…The active surface area of a heterogeneous catalyst, along with proper protic solvents and reagents, could be used for multiple reduction reactions. The selection of solvents and reagents is also crucial due to the increasing environmental concern, for example, reducing nitrobenzene requires strong hydrogen sources, generally accomplished by reducing agents. − For the same, reduction reactions involving the use of green solvents such as methanol and water and green reducing agents, which leave no residues after the reaction, such as hydrazine hydrate (N 2 H 4 ·H 2 O) (only H 2 and N 2 gases as byproducts), are always favorable over conventional methodologies. Additionally, a protic solvent also plays a significant role in dispersing the reactant well and enriching the reaction medium with hydrogen .…”