Nitroarene reduction has played a crucial role in the environment remediation and public health. However, few research studies have been undertaken regarding the use of infinite coordination polymer-based catalysts in this process. Herein, we are looking for a way to catalyze the reduction of nitroarenes using a new and well-designed coordination polymer-based palladium catalyst. The Co-BDC-NH 2 coordination polymer was prepared through a co-precipitation reaction between 2-amino-1,4-benzenedicarboxylic acid as a linker and the cobalt cation as a node. Functionalization of the prepared Co-BDC-NH 2 with 2-pyridinecarboxaldehyde and subsequent metallation with a Pd cation led to the formation of the final catalyst, i.e., Co-BDC-NH 2 -py-Pd. It has been specified that palladium species substantially contribute to the reduction of nitroarenes in the presence of hydrazine hydrate (N 2 H 4 •H 2 O). The highest conversion (100%) of nitroarenes to the corresponding amines was achieved under relatively mild conditions. This heterogeneous catalyst was able to catalyze the reduction of nitroarenes to desired products without changing other substituents. The reusability and stability of the catalyst were confirmed through four consecutive reduction tests without a major decrease in catalytic activity.

Lacunary polyoxometalates (LPOMs), a class of anionic metal oxide clusters, are promising materials as catalysts, photocatalysts, and electrocatalysts. Designing and functionalizing this type of compound are key factors for the discovery and development of novel materials. Herein, a new lacunary polyoxometalate-based compound was designed as a heterogeneous catalyst, prepared through functionalization of a lacunary Keggin-type polyoxometalate, i.e., [PMo11O39]7–, with 3-aminopropyltrimethoxysilane (APTS) and 2-pyridine carboxaldehyde. Subsequent reactions of this compound with Cu2+ ions led to the desired catalyst, LPMo-Cu. The catalytic activity of the obtained LPMo-Cu was examined in nitroarene reduction using sodium borohydride as a reducing agent in aqueous solution. It was specified that the synthesized LPMo-Cu exhibits high catalytic efficiency in the reduction of a wide variety of nitroarenes in a short time (5 min). Furthermore, the stability and recoverability of the prepared material were proved as a result of four consecutive reduction cycles without a significant decrease in its efficiency.