Fabrication of ultra‐small ruthenium nanoparticles on porous modified reduced graphene oxide and its application in solvent‐free oxidation of cyclohexene with molecular oxygen

Abstract

In the present work, ruthenium nanoparticles were synthesized on functionalized reduced graphene oxide (rGO). First, the surface of rGO was modified with two para‐arsanilic acid and dithiooxamide promoters to create the rGO with scattered hydrophilic positions. The ruthenium nanoparticles were synthesized and immobilized simultaneously in small hydrophilic micro‐reactors under mild conditions. Characterization of the synthesized nanocatalyst was confirmed with different techniques, such as transmission electron microscopy (TEM), X‐ray diffraction, Fourier transform‐infrared and scanning electron microscopy. TEM images of the synthesized catalyst show the Ru nanoparticles have diameters less than 6 nm. The designed nanocatalyst was investigated for the selective liquid phase oxidation of cyclohexene with molecular oxygen in an autoclave under solvent‐free conditions, which obtained a maximum of 91% conversion and 90% selectivity under optimized conditions. The catalytic activity over rGO‐AO‐TO/Ru recycled catalyst remained at a satisfactory state after at least five runs.

Evaluation of functionalized reduced graphene oxide upgraded with gold nanoparticles as a hybrid nanocatalyst for the solvent-free oxidation of cyclohexene by molecular oxygen

“…To synthesize rGO-dithiooxamide/Au hybrid catalyst, GO was synthesized from graphite powder using modified Hummers method and reduced to rGO based on the reaction with hydrazine as a reducing agent via a chemical method. Modification of the surface of rGO was then performed by p-aminophenylacetic acid via a well-documented method of forming diazonium in the presence of nitrous acid [36]. Then, for further modification, carboxylic acid groups were activated with SOCl 2 on the surface of modified rGO and subsequently reacted with dithiooxamide.…”

“…Graphene oxide (GO) was synthesized in accordance with the Hummers method using the commercially obtained graphite [34,35]. Next, prepared GO was converted to reduced graphene oxide (rGO) through a chemical procedure.…”

“…Herein, in continuation of our previous works [32][33][34][35][36], a novel approach is employed to fabricate rGO-dithiooxamide/Au hybrid nanocatalyst. Graphene oxide (GO) was synthesized using graphite and chemically converted to reduced graphene oxide (rGO).…”

MIL‐53(Fe)/rGO: A new material applied in an electrochemical sensor for detection of Cd(II) ions in aqueous solutions

“…With regard to rGO's pattern, a single wide diffraction peak at 26.0° corresponding to (002) lattice of rGO is visible. [23,24] In the case of MIL-53(Fe)'s XRD pattern, two peaks appearing at 9.2 and 11.2° are characteristic of MIL-53(Fe). [25] And, in the nanocomposite's XRD pattern, the presence of three peaks at 9.5, 10.9, and 26.0° is specific to MIL-53(Fe) and rGO components.…”

Multilayer‐Functionalized Reduced Graphene Oxide Decorated with Gold Nanoparticles as a Designed Nanonanocatalyst for the Selective Oxidation of Cyclohexene by Molecular Oxygen in a Solvent‐Free System

“…Many noble metal catalytic systems such as Au, Pd, Mn, Cu, Ru, Wand etc. were used as oxidation catalysts in the presence of molecular oxygen . Compared to other noble metals, supported Au nanoparticles exhibit higher stability toward oxygen deactivation and higher selectivity to allylic oxidation, being a promising catalyst for such application.…”