A proficient catalytic reduction of nitroarenes and organic dyes using MOF-derived palladated nano-hydroxyapatite

Abstract

In this study, a heterogeneous metal–organic framework catalyst was meticulously prepared and extensively employed for the reduction of nitroarenes, congo red, and methylene blue. The catalyst was synthesized using a straightforward method, resulting in the formation of nanorods with well-defined morphology. These nanorods, composed of nanorod-hydroxyapatite, served as an exceptional and heterogeneous support for the fabrication of a metal–organic framework composite. In the following, surface functionalization was carried out using asparagine and TAZ-IMI, which was prepared by combining imidazole and cyanuric chloride. To enhance the catalytic performance, Pd(OAc)₂ was immobilized onto the composite, leading to the formation of a novel n-HA@SiO₂–ASP–Pd–TAZ–IMI catalyst. Extensive characterization studies were conducted to confirm the successful formation and structural integrity of the catalyst. The n-HA@SiO₂–ASP–Pd–TAZ–IMI catalyst exhibited remarkable catalytic activity in the reduction of nitro compounds, utilizing NaBH₄ as the reducing agent, resulting in excellent yields. Notably, the catalyst demonstrated excellent recyclability, as it could be easily reused up to three times with only a slight decrease in reaction yield.