Nano NiO/AlMCM‐41, a green synergistic, highly efficient and recyclable catalyst for the reduction of nitrophenols

Abstract

Highly ordered mesoporous molecular sieves AlMCM‐41 and a new NiO/AlMCM‐41 nanocomposite were synthesized using a sol–gel method. Fourier transform infrared (FT‐IR) spectroscopy, X‐ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), and N2 adsorption desorption analyses were used to examine the structure, morphology, size and phase composition of the synthesized NiO/AlMCM‐41 nanocomposites. AlMCM‐41 embedded with NiO nanoparticles was subsequently prepared using different nickel loadings in a direct synthetic route. The results show the successful deposition of NiO nanoparticles onto the framework of AlMCM‐41. AlMCM‐41 provides enormous benefits such as environmentally safe, economic viability and porosity when used as support for NiO nanoparticles. The excellent catalytic activities of AlMCM‐41 and NiO/AlMCM‐41 were investigated for the reduction of nitrophenols (4‐NP, 2‐NP) to aminophenols (4‐AP, 2‐AP) in water at ambient temperature. The best observed performance of reduction of NP with 100% conversion into analogous amino derivatives occurred within 6 min with an estimated rate constant of 0.46 min−1. The efficiency of reduction was observed to increase as a function of NiO enrichment. The NiO/AlMCM‐41 nanocomposite could be recycled and reused up to five times without noticeable change in its structure and activity. These properties make NiO/AlMCM‐41 nanocomposite an ideal platform to study various heterogeneous catalytic processes which can have application in purification, catalysis, sensing devices, and green chemistry.

Solvent‐free synthesis of propargylamines via A3 coupling reaction and organic pollutant degradation in aqueous condition using Cu/C catalyst

“…paracetamol). [ 25,44 ] To date, noble metals or transition metals have received much attention for the catalytic reduction of 4‐NP. However, developing simple, low metal loading, low‐cost, green process with less hazardous catalysts having superior performance for the catalytic reduction of 4‐NP is still highly demanded.…”

“…[ 24 ] All these reported systems require high‐temperature and high‐pressure reactors, strong acid media, toxic solvents, and high catalyst loadings, but generally produce low yields. [ 25 ] In addition, these reported technologies dealt only with the catalytic reduction of 4‐NP, and without separation and purification of resulting products. As such, the development of more effective heterogenous catalysts for the reduction of nitro‐substituted compounds remains an important area of concern.…”

A facile hydrothermal synthesis of high-efficient NiO nanocatalyst for preparation of 3,4-dihydropyrimidin-2(1H)-ones

“…Nickel oxide (NiO) is a broad band gap antiferromagnetic p-type semiconductor 2 . NiO nanoparticles are used in gas sensors 3 , batteries 4 , transparent conducting layers 5 , solar thermal absorbers 6 , electrochromic devices 7 , optical fibers 8 , smart windows 9 and photocatalysts 10 .…”

Introduction of Ag/CuO/MCM‐48 as an efficient catalyst for the one‐pot synthesis of novel pyran‐pyrrole hybrids

“…In catalysis, they have been recognized as a versatile support to generate numerous hybrid materials. [14][15][16][17][18][19][20][21] Among all the OMS materials developed, MCM-48 with striking cubic structure comprising of 3D interconnected pore network has gained enormous interest in this area. Catalytic activity in heterocyclic synthesis, [22,23] hydrogenation, [24,25] esterification, [26] epoxidation, [27] β-amino carbonyl synthesis, [28] Ulmann reaction, [29] oxidation of olefins, cyclic ketones, sulfides, thiols, [30,31] alkylation of phenol [32] and acting as a photocatalyst [33,34] are some of these applications.…”

“…Such a vast development is due to their fascinating structural properties, including large pore volumes, tunable pore size, easy functionalization of surface area and good stabilities. In catalysis, they have been recognized as a versatile support to generate numerous hybrid materials . Among all the OMS materials developed, MCM‐48 with striking cubic structure comprising of 3D interconnected pore network has gained enormous interest in this area.…”