Aerobic oxidation of cyclohexane with γ-alumina supported metallophthalocyanines in the gas phase

Vanadium‐Substituted Tungstophosphoric Acids as Efficient Catalysts for Visible‐Light‐Driven Oxygenation of Cyclohexane by Dioxygen

“…This may be because an excessofw ater interferesw ith the formation of a D-A complex [PW 9 V 3 O 40 6À -HCl].N otably,t he phenomena described above also existed in the PW 10 V 2 system mediated by HClgas or its aqueous solution ( Figure SI 3), but did not occur for PW 12 or PW 11 V 1 acid (Figure SI 4a nd 5). It is concluded from these findings that i) the oxidative capacity of PWV acids is weakened in the presence of water and this weakening effecti sp roportionalt ot he concentration of water;i i) the additiveH Cl gas or its aqueous solution can playapositive role in improving the redox recycling between V 5 + and V 4 + ions in PW 10 -HCl],s hould be responsible for the HClaqueous solution-promoted photocatalysis oxidation;i ii)the addition of as uitable amount of water to the HCl gas-mediated system does not result in an obvious decrease in the reoxidation activity of PW 9 V 3 acid and can efficiently preserve its redoxr ecycling, but the addition of an excess amount of water will cause very unfavorable effects on the catalyst's redox recycling and especially the formation of [PW 9 V 3 O 40 6À -HCl], which agreesw ell with the reactionr esults describeda bove.…”

Tuning of Activated Carbon for Solvent-Free Oxidation of Cyclohexane

“…Moreover, most of these catalysts have been utilized in the presence of a solvent [15,16] and an expensive oxidant [17]. Several catalytic systems, such as FeRu, FeCo nanoclusters, supported Co catalyst, polymer supported cobaltous palmitate, and Co-salen complex immobilized on silica [18], Au/MCM-41 [13], gold nanoparticles immobilized upon mesoporous silica [19], Au nanoclusters on hydroxyapatite [17], metallophthalocyanines supported on -alumina [20], and chromium containing silicate [21], have been devised in solvent-free condition and presence of molecular oxygen. These catalysts in general have limitations of poor catalytic activity, loss of sensitivity, low selectivity, and high cost.…”

Probing the Catalytic Activity of Tin-Platinum Decorated Graphene; Liquid Phase Oxidation of Cyclohexane

“…The catalytic oxidation of cyclohexane to KA oil (KA oil: cyclohexanol and cyclohexanone) is of immense significance as it has a broad range of industrial applications [1]. It is used in the synthesis of Nylon-6, Nylon-66 and also used as an excellent solvent for coating processes [2].…”

“…Other uses of cyclohexanone include their use as starting materials in the synthesis of insecticides, herbicides, and pharmaceuticals [5]. The modern industrial process for oxidation of cyclohexane to a mixture of cyclohexanol and cyclohexanone relies on a cobalt salt as a catalyst, a temperature range of 150˝C-160˝C, and pressure of air around about 1 atm under homogeneous reaction condition that results in the conversion of less than 6% and selectivity of cyclohexanol and cyclohexanone of around 80% [1]. Since, the process is characterized by low % conversion, high operational cost, and a tedious recovery of the catalyst from the reaction mixture, researchers have been exploring various alternatives to overcome these drawbacks.…”

“…Gold nanoparticles embedded in amorphous silica have shown a high catalytic activity and selectivity at 150˝C and 14.8 atm O 2 for 3 h. However, this system also required tert-butyl hydroperoxide as initiator. Some other catalysts including metals such as Co, Fe, and Mn supported on γ-alumina, and supported pthalocyanines have also been reported to carry high activity and selectivity for the gas phase selective oxidation of C 6 H 6 to KA oil, in the absence of solvents and reducing agents, under 1 atm of air pressure in the temperature range of 300˝C-400˝C [1].…”