Development of High-Efficiency, Magnetically Separable Palladium-Decorated Manganese-Ferrite Catalyst for Nitrobenzene Hydrogenation

Abstract

Aniline (AN) is one of the most important compounds in the chemical industry and is prepared by the catalytic hydrogenation of nitrobenzene (NB). The development of novel, multifunctional catalysts which are easily recoverable from the reaction mixture is, therefore, of paramount importance. Compared to conventional filtration, magnetic separation is favored because it is cheaper and more facile. For satisfying these requirements, we developed manganese ferrite (MnFe2O4)–supported, magnetically separable palladium catalysts with high catalytic activity in the hydrogenation of nitrobenzene to aniline. In addition to high NB conversion and AN yield, remarkable aniline selectivity (above 96 n/n%) was achieved. Surprisingly, the magnetic support alone also shows moderate catalytic activity even without noble metals, and thus, up to 94 n/n% nitrobenzene conversion, along with 47 n/n% aniline yield, are attainable. After adding palladium nanoparticles to the support, the combined catalytic activity of the two nanomaterials yielded a fast, efficient, and highly selective catalyst. During the test of the Pd/MnFe2O4 catalyst in NB hydrogenation, no by-products were detected, and consequently, above 96 n/n% aniline yield and 96 n/n% selectivity were achieved. The activity of the Pd/MnFe2O4 catalyst was not particularly sensitive to the hydrogenation temperature, and reuse tests indicate its applicability in at least four cycles without regeneration. The remarkable catalytic activity and other favorable properties can make our catalyst potentially applicable to both NB hydrogenation and other similar or slightly different reactions.

Catalytic Hydrogenation of Nitroarenes over Ag33 Nanoclusters: The Ligand Effect

“…The energy barriers for the reaction were 1.83 (hydrogenation), 1.10 (desorption), and 0.52 eV (adsorption) for Ag 33 –PET, Ag 33 -p-BMTM, and Ag 33 -p-BMTC, respectively, which agreed with its catalytic activity for the reduction of 4-nitrophenol (Figure f). These results were in accord with the previous reports that ligand on the catalyst played key roles in the hydrogenation reaction. − …”

Ferrite Nanoparticles as Catalysts in Organic Reactions: A Mini Review

“…The catalyst was able to remov of PNP in 7 h using 4 mM of PMS and 0.5 g L −1 of MSN at 40 °C and pH 5.8. In a recent development, MnFe 2 O 4 -supported magnetically separable palladium catalysts were reported for the hydrogenation of nitrobenzene to aniline (Scheme 33), showing excellent catalytic activity with no by-products and above 96% aniline yield [156].…”

“…Excellent catalytic activity with 96% aniline yield and no by-products [155] Hydrogenation of nitrobenzene to aniline Catalyst reusable up to four cycles without loss in catalytic performance [156] Synergistic process of photocatalysis and adsorption for the degradation of Reactive Red 4 (RR4) dye…”

Highly Efficient Catalytic Reduction of Nitrobenzene Using Cu@C Based on a Novel Cu–MOF Precursor

“…Pd, Pt, and other noble metal catalysts have shown very high catalytic activity in nitrobenzene reduction in recent decades [10]. Neeli Chinna Krishna Prasad et al [11] syn-thesized a Pd/NH 2 -UiO-66 catalyst using the anion exchange method, and the reduction of nitrobenzene was carried out with formic acid as the reducing agent under mild conditions.…”