Synthesis, structure and catalytic activity of the supported Ni catalysts for highly efficient one-step hydrogenation of 1,5-dinitronaphthalene to 1,5-diaminodecahydronaphthalene

Reduction of Nitro Compounds Using 3d-Non-Noble Metal Catalysts

The reduction of nitro compounds to the corresponding amines is one of the most utilized catalytic processes in the fine and bulk chemical industry. The latest development of catalysts with cheap metals like Fe, Co, Ni, and Cu has led to their tremendous achievements over the last years prompting their greater application as "standard" catalysts. In this review, we will comprehensively discuss the use of homogeneous and heterogeneous catalysts based on non-noble 3d-metals for the reduction of nitro compounds using various reductants. The different systems will be revised considering both the catalytic performances and synthetic aspects highlighting also their advantages and disadvantages.

Synthesis of 3D N-doped graphene/carbon nanotube hybrids with encapsulated Ni NPs and their catalytic application in the hydrogenation of nitroarenes

A Ni@N-CNTs-GS catalyst prepared via pyrolysis is shown to be active and stable for the hydrogenation of nitroarenes to anilines via a direct route.

Microwave-activated Ni/carbon catalysts for highly selective hydrogenation of nitrobenzene to cyclohexylamine

Biocarbon supported Ni catalysts have been prepared by facile impregnation of Ni species by microwave-heating and used for selective hydrogenation of nitrobenzene to cyclohexylamine. These catalysts were characterized by X-ray diffraction, Raman spectra, N2 sorption measurement, X-ray photoelectron spectroscopy, temperature programmed reduction of H2 and H2 temperature-programmed desorption. The morphology and particle size of catalysts were imaged by scanning electron microscope and transmission electron microscope. For the hydrogenation of nitrobenzene to cyclohexylamine, 10%Ni/CSC-II(b) exhibits the best catalytic activity to achieve 100 mol% conversion of nitrobenzene and 96.7% selectivity of cyclohexylamine under reaction conditions of 2.0 MPa H2 and 200 °C, ascribed to high dispersion of Ni species and formation of nanosized Ni particles on the support aided by microwave-heating. Thus-prepared Ni/CSC catalyst is greatly activated, in which the addition of precious metal like Rh is totally avoided.

Highly selective one-step hydrogenation of nitrobenzene to cyclohexylamine over the supported 10% Ni/carbon catalysts doped with 3‰ Rh

The catalyst 3‰ Rh–10% Ni/CSC exhibits an excellent performance to achieve 100 mol% conversion of nitrobenzene and 91.6% selectivity of fully-hydrogenated cyclohexylamine under conditions of 3.5 MPa H₂ and 140 °C.