Facile Fabrication of Pumice‐Supported Palladium Nanocatalyst for the Catalytic Reduction of Nitroaromatic Compounds

ABSTRACT

In this study, a new palladium (Pd) nanocatalyst was prepared using pumice (PM) as an alternative support material for the heterogeneous reduction of nitroaromatic compounds (NACs). Pd nanoparticles were immobilized on the PM surface, and the designed Pd@PM nanostructure was characterized using X‐ray diffraction (XRD), Field‐emission scanning electron microscopy (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDS), and transmission electron microscopy (TEM) analyses. The synthesized Pd@PM nanocatalyst was successfully applied in the catalytic reduction of NACs, such as 2‐nitroaniline (2‐NA), 3‐nitroanisole (3‐NAS), 4‐nitroaniline (4‐NA), 4‐nitrobenzoic acid (4‐NBA), and 4‐nitro‐o‐phenylenediamine (4‐NPD). Pd@PM showed good catalytic performance by efficiently supporting the reduction of NACs in short reaction times within 48–420 s. The formation of the corresponding amine products was confirmed by high‐performance liquid chromatography (HPLC), with distinct retention times supporting the successful conversion of all substrates. Furthermore, the reusability of the Pd@PM nanocatalyst was investigated over five consecutive cycles, demonstrating good reusability, although a gradual decrease in catalytic performance was observed during the later cycles. The main innovation of this study is the direct use of naturally porous pumice as a simple, low‐cost support for Pd nanoparticles, providing a recoverable heterogeneous platform for rapid aqueous‐phase conversion of hazardous nitroaromatic pollutants into value‐added amines.