Gold nanoparticles supported on ionic‐liquid‐functionalized cellulose (Au@CIL): A heterogeneous catalyst for the selective reduction of aromatic nitro compounds

Abstract

In response to the increasing need for green and cost-effective catalysts, a novel biomass-derived heterogeneous catalyst that is effective in a number of environmentally friendly applications has been synthesized. The heterogeneous catalyst (Au@CIL), composed of ionic-liquid-functionalized cellulose embedded with Au nanoparticles (NPs), was developed for the selective reduction of the nitro group. The Au NPs are formed by the reduction of Au 3+ to Au 0 with ascorbic acid while embedded in the solid support system. The presence of embedded Au NPs was confirmed using infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, zeta-potential measurements, energy-dispersive X-ray analysis, elemental dot mapping, and atomic force microscopy. In water at 30 C, the heterogeneous catalyst Au@CIL selectively transforms aromatic nitro compounds into the corresponding amines in the presence of other functional groups, such as hydroxy, amino, aldehyde, carboxylic acid, and amide.

Chitosan–poly(vinyl alcohol)–ionic liquid-grafted hydrogel for treating wastewater

“…After evaporation, the IL was obtained and used without further purification. 33 1 H NMR (400 MHz, DMSO-d 6 ) δ 7.57 (d, J = 2.9 Hz, 2H), 7.18 (dd, J = 6.1, 3.1 Hz, 2H), 6.06–5.93 (m, 1H), 5.33 (dd, J = 16.8, 1.3 Hz, 2H), 5.11 (dd, J = 9.9, 1.5 Hz, 2H), 4.08 (d, J = 7.3 Hz, 2H), 1.74 (t, J = 6.9 Hz, 2H), 1.34–1.20 (m, 10H), 0.81 (t, J = 6.8 Hz, 3H). 13 C NMR (100 MHz, DMSO-d 6 ) δ 144.0, 144.8, 135.1, 134.6, 124.5, 123.6, 120.0, 115.4, 111.8, 47.5, 35.8, 34.7, 32.8, 29.1, 28.6, 28.1, 22.6, 14.5.…”

Dual Ionic Liquid-Functionalized Cellulosic Materials: Thermal, Conductive, and Morphological Properties

“…33 More recently, Singh et al developed a heterogeneous catalyst composed of benzimidazolium-functionalized cellulose embedded with gold nanoparticles for the purpose of reducing aromatic nitro groups to amines in water. 34 Tan and co-workers functionalized starch with 1,2,3-triazolium and pyridinium groups, and the resulting materials were found to be morphologically amorphous as determined from X-ray diffraction data. 35 The materials also exhibited antifungal activity against three different plantthreatening fungi.…”

“…Ammonium- and imidazolium-functionalized cellulosic materials have also been reported in carbon dioxide absorption studies . More recently, Singh et al developed a heterogeneous catalyst composed of benzimidazolium-functionalized cellulose embedded with gold nanoparticles for the purpose of reducing aromatic nitro groups to amines in water . Tan and co-workers functionalized starch with 1,2,3-triazolium and pyridinium groups, and the resulting materials were found to be morphologically amorphous as determined from X-ray diffraction data .…”