Nitroarene reduction: a trusted model reaction to test nanoparticle catalysts

Abstract

Nitrophenol reduction to aminophenol with a reducing agent is conveniently carried out in aqueous medium mainly with a metal or metal oxide catalyst. This reduction is presently considered as a benchmark reaction to test a catalyst nanoparticle. Thousands of original reports have enriched this field of nanoparticle catalyzed reaction. Synthesis of different metal and metal oxide nanoparticles and their composites along with their role as catalysts for nitrophenol reduction with varying reducing agents have been elucidated here. The progress of the reaction is conveniently monitored by UV-visible spectrophotometry and hence it becomes a universally accepted model reaction. In this review we have discussed the reaction kinetics considering its elegance and importance enlightening the long known Langmuir-Hinshelwood mechanism and Eley-Rideal mechanism at length, along with a few other mechanisms recently reported. A brief description of the synthetic procedures of various nanoparticles and their respective catalytic behaviour towards nitroarene reduction has also been accounted here.

Reaction rate of a composite core–shell nanoreactor with multiple nanocatalysts

“…Once the the coefficients have been determined, the rate constant can be obtained from eq. (15). Recalling the definitions (19) and making use of known properties of solid spherical harmonics, it is easy to see that…”

“…The present model has been designed to describe the well-studied core-shell systems [8,9], but is equally adapted to the study of systems where catalytic centers are embedded in homogeneous microgels [14]. Up to now, most of the experimental work has been done using the reduction of 4-nitrophenol by borohydride ions in aqueous solution [15,16]. This reaction can be regarded as a model reaction [17], since it can be monitored with high precision thus leading to very accurate kinetic data.…”

Reusable and Flexible Heterogeneous Catalyst for Reduction of TNT by Pd Nanocube Decorated ZnO Nanolayers onto Electrospun Polymeric Nanofibers

“…When Pd nanostructures are covered with ligands or embedded in polymers surface pollution or decrease in catalytic activity is observed due to reducement in the coordination sites of the metal nanoparticles. [56][57] For the catalytic degradation of TNT,active sites of the Pd NC for nitro groups together with 5 ring intermediate is essential. [58] UV-visible absorption technique can be used to determine the concentration of the TNT reduced by the Pd@MPTMS@ZnO@PAN-NF.…”

CuPd Bimetallic Nanoparticles Supported on Magnesium Oxide as an Active and Stable Catalyst for the Reduction of 4-Nitrophenol to 4-Aminophenol

“…The mechanism of such a reaction is well-understood and its kinetics easy to follow by UV-Vis spectroscopy. Since this reaction was first reported in 2002 by T. Pal et al [4] and K. Esumi et al [5], a huge number of research groups have used it in order to evaluate the catalytic properties (kinetics, stability) in the aqueous phase of lab-synthetized metal nanoparticles [6]. Although more cost-effective metal such as copper has drawn high attention in recent years [7], as we exposed in a former work [8], the noble and costly metal catalysts such as gold [9,10], Pt [11] or Ag [12], have been the focus of most of the reported literature.…”