Magnetically recoverable catalytic Co–Co2B nanocomposites for the chemoselective reduction of aromatic nitro compounds

Abstract

Magnetically recoverable and recyclable Co-Co 2 B nanocomposites are described for the catalytic and chemoselective reduction of nitroarenes using two different hydrogen sources, sodium borohydride and hydrazine hydrate. Both the systems display an interesting chemoselective reduction switch. The kinetics of reduction of nitroaromatics were studied for the first time and follow nitroreductase enzyme-like kinetics with exceedingly high K cat (5.2 6 10 4 s 21 ) and K cat /K M (4.4 6 10 6 M 21 s 21 ) values, reaching the state of catalytic perfection. The recyclability of the catalyst system was studied by magnetically recovering the nano composite catalyst.

Application of Co/Ti film catalysts with different nanostructures in the reduction of p-nitrophenol to p-aminophenol

“…However, transformation of PNP to PAN catalyzed by Co nanostructures has been seldom a concern, and there are only a few reports regarding the catalytic reduction of PNP using metallic Co nanostructures or Co (zero valence) containing nanocomposites as catalysts. 11,28,29 In particular, nanosized Co-catalyzed reduction of PNP to PAP using N 2 H 4 •H 2 O as a reducing agent has not been reported previously, to the best of our knowledge.…”

One-step synthesis of magnetically recyclable Co@BN core–shell nanocatalysts for catalytic reduction of nitroarenes

“…p-OH, p-NH 2 , p-OCH 3 ) appears to be more easily reduced than those with electron-withdrawing groups (e.g. p-Cl), [60][61][62] while for hydrophobic 4-methylnitrobenzene poor water-solubility restricts its reaction activity. 61 The results also suggest that the Co@BN nanocatalysts possess excellent catalytic activity for the hydrogenation of nitroarenes with different substituent groups.…”

“…hydroxyl, methyl) for nitroarenes. [60][61][62] Among these reactants, nitroarenes with electron-donating groups (e.g. p-OH, p-NH 2 , p-OCH 3 ) appears to be more easily reduced than those with electron-withdrawing groups (e.g.…”

Formation of a gold–carbon dot nanocomposite with superior catalytic ability for the reduction of aromatic nitro groups in water

“…m-Dinitrobenzene was reduced to m-phenylenediamine in the presence of NaBH 4 and our nanocomposite in aqueous phosphate buffer. 14 The corresponding change in the UV-vis spectra also demonstrated this fact (Fig. S7, ESI †).…”

“…12 The conversion of p-aminophenol from its nitro analogue is a reaction of versatile applications that includes antipyretic or analgesic drug development, dye industry, and corrosion removal. 13,14 Moreover, the reaction does not proceed in the absence of any catalyst. The progression of the reaction can be easily monitored by observing the rate at which the characteristic 400 nm peak of p-nitrophenol decreases as it converts to p-aminophenol with the generation of a new peak at 300 nm (Fig.…”