A Review on Chemoselective Reduction of Nitroarenes for Wastewater Remediation Using Biochar Supported Metal Catalysts: Kinetic and Mechanistic Studies

A stable hybrid catalyst (POM-PPPh3/L/Ni) for the reduction of toxic nitroarene compounds in water

“…In accordance with Scheme 1, the desired Schiff base ligand (L) was initially prepared from the combination of salicylaldehyde and diethylenetriamine (Scheme 1-red frame, 1 H NMR and FT-IR spectra of the L can be seen in Fig. S1 and S2 †).…”

“…The reaction mixture was refluxed for 24 h to obtain a clear yellow solution, which was evaporated to afford an orange liquid. The final product was characterized by 1 H NMR and FT-IR spectroscopy. 28 1 H NMR (300 MHz, DMSO-d 6 ) δ: 2.9 (4H, -CH 2 ), 3.6 (4H, -CH 2 ), 6-7.5 (8H, H-aromatic), 8.28 (2H, H-CvN), 13-13.2 (2H, OH) ppm (Fig.…”

“…After filtration, the prepared sediment was washed with methanol (3 × 10 mL) and distilled water (3 × 10 mL) and dried in air. 1 H NMR (300 MHz, DMSO-d 6 ) δ: 2.07 ppm (2H, -CH 2 ), 3.65 ppm (4H, -CH 2 ), 7.78-7.91 ppm (15H, CH of aromatic rings of PPh 3 ) (Fig. S4 †).…”

“…These persistent, stable, and toxic nitro compounds ( particularly nitrobenzene) are carcinogenic pollutants even at low concentrations. 1 Catalytic nitroarene reduction to aminoarenes is considered a great solution to overcome this problem. [2][3][4][5] The obtained aminoarenes have been introduced as effective intermediates in a large number of industries including pharmaceuticals, pigments and dyes, agrochemicals, and polymers.…”

“…Meanwhile, the high surface energy of nanosized materials intensifies their instability and leads to agglomeration and decreased catalytic activity. 20 † Electronic supplementary information (ESI) available: Details of the used chemicals and equipment, 1 H NMR and FT-IR spectra of the prepared Schiff base, 31 P NMR spectrum of a POM, 1 H NMR and 31 P NMR spectra of POM-PPPh 3 , EDX spectrum of POM-PPPh 3 /L/Ni, UV-visible spectra of reduction of various nitroaromatic compounds in the presence of POM-PPPh 3 /L/Ni, FT-IR spectrum, XRD pattern, and FESEM image of POM-PPPh 3 /L/Ni, and gas chromatography (GC) results and the mass spectra of the product of NB reduction reaction after 5 min. See DOI: https://doi.org/10.1039/d4dt00909f…”