Promoting effect of ionic liquids in liquid-phase oxidation of cyclohexane with a mixture of О2 and Н2

Recent Advances in the Direct Synthesis of H2O2

“…The in situ generation of H 2 O 2 for the oxidation of cyclohexanone has recently been studied by Kuznetsova and co‐workers utilising Pt based catalysts. It is reported that the addition of small quantities of ionic liquids containing Br‐ and HSO 4 − anions are able to stabilise the peroxide‐intermediates, resulting in an enhanced yields of KA oil ,. A further study by Li et al.…”

The Direct Synthesis of H2O2 and Selective Oxidation of Methane to Methanol Using HZSM-5 Supported AuPd Catalysts

“…We [21][22][23] have previously reported the efficacy of AuPd nanoparticles supported on a range of zeolites, for the production of H 2 O 2 as well as their use in the oxidation of cyclohexene and 2-butenol [24]. Further work has demonstrated the feasibility of in situ H 2 O 2 generation in the hydroxylation of benzene [25,26] and cyclohexane [27].…”

Synthesis and Characterization of Oligomeric Ionic Liquid/Heteropoly Acid Composite as a New Heterogeneous Catalyst through Anion-Exchange Method for Selective Cyclohexane Oxidation with Molecular Oxygen under Solvent-Free Conditions

“…The oxidation of cyclohexane is an extremely important industrial process because it changes a low-cost material into highly valuable products such as cyclohexanone, cyclohexanol, and adipic acid; hence, there has been great attention to process from the past to the present. − Many of the methods, , oxidants such as molecular oxygen, ,,, hydrogen peroxide, − tert -butylhydroperoxide, , as well as different catalysts such as metal mixed oxides, , molecular sieves, , (supported) metal complexes, ,,− (supported) metal ions and nanoparticles, ,,, ionic liquids, ,,, heteropoly acids (HPAs) and their related polyoxometals (POMs), ,,, and so on have been investigated and proposed for the oxidation of cyclohexane.…”

“…HPAs and their related POMs are thermally and oxidatively stable metal–oxygen anionic clusters of transition metals of group 6 (Mo, W) or less commonly group 5 (V, Nb, Ta) in their high oxidation states which makes them very strong oxidants in the field of organic oxidation. ,,− The use of these catalysts is usually associated with the main oxidizing agent that improves the conversion and selectivity of the reactant. , Despite the high oxidation efficiency, homogeneity is the major challenge with these catalysts because of problems such as corrosion of the reactor, catalyst removal, and waste formation, and so on . For the preparation of insoluble, solid, or heterogeneous HPA catalysts, salt formation with acidic large cations such as cesium, ammonium, or cerium, as well as, the inclusion of them in silica or other supports have been reported. , A serious problem with the solid HPA catalysts (acidic cesium, ammonium, or cerium salt of HPAs) is their deactivation during organic reactions due to the formation of carbonaceous deposit (coke) on the catalyst surface .…”