Ni/graphene Nanostructure and Its Electron-Enhanced Catalytic Action for Hydrogenation Reaction of Nitrophenol

Abstract

heterostructured Ni/ graphene nanocomposites were constructed via electrostaticinduced spread by following in situ-reduction growth process for magnetically recyclable catalysis of p-nitrophenol to paminophenol. The heterostructures with large 2D surface and moderate inflexibility enable the superior catalytic activity and selectivity toward hydrogenation reaction for p-nitrophenol. On the basis of high-efficiency utilization of Ni Nps catalysis activity and electron-enhanced effect from graphene, the coupling effect of Ni/graphene magnetic nanocomposites can lead to highly catalytic activity for the hydrogenation reaction of p-nitrophenol with the pseudo-first-order rate constants of 11.7 × 10 −3 s −1 , which is over 2-fold compared to Ni Nps (5.45 × 10 −3 s −1 ) and higher than reported noble metal nanocomposites. Complete conversion of p-nitrophenol was achieved with selectivity to p-aminophenol as high as 90% under atmosphere and room temperature. Additionally, this heterostructured magnetic nanocatalyst can be efficiently recycled with long lifetime and stability over 10 successive cycles. This work displayed the value of non-noble metal/graphene nanocomposites in catalysts development for green chemistry.

Hydrogenation of nitrophenols catalyzed by carbon black-supported nickel nanoparticles under mild conditions

“…Based on the experimental results and the literatures [3,9,21,24], it can be understood that the present reduction process involves the following crucial steps as shown in scheme 1: (1) In the reaction system, the π-π stacking interaction between aromatic nitrophenol molecules and the surface of CB plays an important role in promoting the aromatic entities gaining easier access to Ni NPs.…”

“…Nitroaromatic compounds are being widely used in industrial processes, including the manufacture of dyes, pharmaceuticals, pigments, pesticides, wood preservatives and rubber chemicals [1][2][3][4]. Therefore, nitroaromatic compounds are often presented as water pollutants due to the release in industrial effluents.…”

“…It is known that the reduction products of nitrophenols, aminophenols with lower toxicity are widely used as intermediates for the synthesis of pesticides, medicine, dyes and other fine chemicals [11,12]. As a typical example, p-aminophenol (p-AP) is less poisonous than p-nitrophenol (p-NP), and has become an important intermediate for the production of analgesic and antipyretic drugs such as phenacetin, paracetamol and acetanilide [3,13,14].…”

“…In order to solve these problems, various non-precious metal catalysts [38][39][40], especially nickel-based catalysts [3,[39][40][41] have been developed as economical alternatives in hydrogenation reactions. However, compared with precious metal-based catalysts, the nickel-based systems usually exhibit relatively low activity, require higher temperatures and consume more energy in the process.…”

Basic concepts and recent advances in nitrophenol reduction by gold- and other transition metal nanoparticles

“…The common and most efficient way for the reduction of 4-NP is to introduce NaBH 4 as a reductant and a metal catalyst such as AuNPs [12], AgNPs [13], PdNPs [14], PtNPs [15] and NiNPs [16]. Compared with other metal catalysts, AuNPs have two unique properties: (i) the catalytic activity of gold is directly related to the particle size, and the catalytic activity is only observed at the nanometric scale but not micrometric scale; (ii) Au catalysts are active under mild conditions, even at ambient temperature or less.…”