Nitrogen-doped carbon nanotubes encapsulate cobalt nanoparticles as efficient catalysts for aerobic and solvent-free selective oxidation of hydrocarbons

Abstract

The selective oxidation of hydrocarbons to the corresponding ketones with solvent-free and molecular oxygen as an oxidant is of great importance in academic and industrial fields in view of economy and environment.

Zeolitic Imidazolate Framework-Mediated Synthesis of Co3O4 Nanoparticles Encapsulated in N-Doped Graphitic Carbon as an Efficient Catalyst for Selective Oxidation of Hydrocarbons

“…7 The thermal stability of the as-synthesized ZIF-GO composite has been evaluated by thermogravimetric analysis (TGA). According to the TGA-DSC curves (Fig.S5, SI), it is understood that the ZIF-GO composite was highly stable up to 350ºC.…”

Palladium‐Supported Nanoceria: A Highly Efficient Catalyst for Solvent‐Free Selective Oxidation of Ethylbenzene to Acetophenone

“…High value‐added materials such as resins, flavoring agents, perfumes and pharmaceuticals are produced from acetophenone, a product obtained from the C−H bond activation of a toxic compound occurring naturally in petroleum viz. ethylbenzene . Although several reports suggest the C−H activation of ethylbenzene to acetophenone in the liquid phase, the toxicity and volatile nature of organic solvents poses serious threat to the environment besides increasing the production cost and difficulty of product separation …”

“…al reported the liquid‐phase oxidation of ethylbenzene to acetophenone using a ternary composite of Pd/g‐C 3 N 4 /r‐GO nanocomposites with only 67% conversion at 24 h . Lin et.al in 2017 carried out the solvent‐free conversion of ethylbenzene to acetophenone by Co encapsulated carbon nitride nanotubes, but the use of high‐pressure reaction kettle and high temperature (120 °C) limit its use . Another report by Miao et.al in 2017 suggests the liquid phase oxidation of ethylbenzene to acetophenone by transition metals‐zirconium oxophosphate composites but their method requires long reaction time (24 h) in addition to using of solvents .…”

Recent Advances in Homogeneous Metal-Catalyzed Aerobic C–H Oxidation of Benzylic Compounds

“…For safety and environmental reasons, molecular oxygen is the oxidant of choice in most oxidative transformations, and an increasing number of reports concerning oxidation of arylmethylene compounds under aerobic conditions can be found in the literature [62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78]. Interestingly, although a theoretically easier catalyst-product separation has boosted research on heterogeneous catalysts (e.g., polymer-or montmorillonite clay-supported catalysts, Pd, Au, or Co nanoparticles) [79][80][81][82][83][84][85][86][87][88][89][90][91][92][93], leaching problems and efficiency or selectivity issues [79,85,86,90,93] have encouraged investigations on the development of new homogeneous catalyst systems. This review will cover recent literature from 2000 on the use of homogenous metal catalysts for the aerobic benzylic methylene C-H oxidation leading to aromatic ketones, esters, and amides, with a focus on with a focus on relevant parameters such as reaction yields, substrate:catalyst ratio, selectivity towards target carbonyl compounds, reaction media, and other experimental conditions.…”