Catalytic systems of cumene oxidation based on multiwalled carbon nanotubes

Skorokhodova, T. S.; Ryabova, N. V.

doi:10.1134/s0036024415030164

Cited by 10 publications

(5 citation statements)

References 10 publications

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“…Therefore, in order to increase the CHP productivity, while maintaining the excellent selectivity to CHP, different catalysts have been proposed, either homogeneous or heterogeneous, mainly based on transition metal salts and oxides. [13][14][15][16][17][18][19][20][21] We and others have shown that several Metal-Organic frameworks (MOFs) can be used for the aerobic oxidation (i.e., using only air or oxygen as the oxidant) of activated alkanes, such as tetralin, 22 cyclooctane, 23 indane, 24 and various alkylbenzenes, 25 including cumene. Alternatively, MOFs can also be used as hosts in which other active species, such as metallo-phthalocyanines 26 or metal-oxide nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

“…However, the productivity of such autoxidation processes (expressed in terms of grams of CHP produced per liter of CM and per hour; g L –1 h –1 ) is usually below the desired values. Therefore, in order to increase the CHP productivity, while maintaining the excellent selectivity to CHP, different catalysts have been proposed, either homogeneous or heterogeneous, mainly based on transition metal salts and oxides. − …”

Section: Introductionmentioning

confidence: 99%

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Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal–Organic Frameworks Prepared by a Facile “Green” Aqueous Synthesis

Nowacka

Briantais

Prestipino

et al. 2019

ACS Sustainable Chem. Eng.

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Co-Ni and Mn-Ni bimetallic trimesate MOFs prepared by a fast aqueous synthesis method are excellent and reusable catalysts for the selective oxidation of cumene to cumene hydroperoxide. Isolation of Co 2+ (or Mn 2+ ) in an inert Ni-BTC framework is a good strategy to optimize CHP selectivity above 90%: since only Co 2+ sites catalyze CHP decomposition, a drop of the CHP selectivity is observed as the cobalt content increases.The statistical probability of having isolated Co 2+ sites is calculated as a function of the total cobalt content of the bimetallic compound, assuming homogeneous distribution of Co 2+ ions in the Ni-BTC framework and preferential occupation of terminal sites. Thus, in our best sample, with a Co:Ni ratio of 5:95, 73% of the total Co 2+ ions are isolated so that CHP decomposition/over-oxidation processes at the surface of the catalyst are not likely to occur before CHP desorption. This can explain the excellent CHP selectivity (91%) attained over this material. This "site isolation" effect is further supported by similar findings on Mn-Ni bimetallic compounds.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal–Organic Frameworks Prepared by a Facile “Green” Aqueous Synthesis

Nowacka

Briantais

Prestipino

et al. 2019

ACS Sustainable Chem. Eng.

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“…Active catalysts were also prepared by supporting transition metals on polymeric materials, − showing a very high selectivity (99%) but at low conversion levels (6.8%); interestingly, the reaction rate was 84% faster than that observed in the blank test performed without catalyst (autoinitiated with CHP) under the same conditions . Kobotaeva et al reported the use of Ag nanoparticles supported on multiple-wall carbon nanotubes, achieving 76% selectivity to CHP at 28% cumene conversion.…”

Section: Oxidation Of Cumene To Cumylhydroperoxide (Chp)mentioning

confidence: 99%

Zeolite-Based Catalysis for Phenol Production

Perego

Angelis

Pollesel

et al. 2021

Ind. Eng. Chem. Res.

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Phenol is an important chemical commodity utilized for several applications (e.g., polycarbonate, epoxy–resins, phenolic resins, nylon). Its conventional production starts from benzene and propylene and is based on a series of reaction steps most of which are catalyzed by acid catalysts. Besides this technology other ones have been considered during the last decades, starting from other reactants and catalysts. Looking at the catalyst types both already in use or under evaluation, it is interesting to note that zeolites, as acidic catalysts or red-ox catalysts, were widely investigated. Therefore, the production of phenol represents a fascinating example of how zeolite catalysis contributes to improving the sustainability of these chemical processes by displacing the previous large use of corrosive and dangerous liquid acids and improving overall selectivity, which reduces the side production of wastes. Aromatic alkylation, transalkylation, and disproportionation, oxidations, rearrangements, oligomerization, and cracking are the reactions occurring in phenol production technologies, but also key unit operations in refineries and the chemical industry. A review of the zeolite catalysts utilized and proposed by major licensors and research groups in these technologies is provided as well as a discussion of key process differences and recent advances.

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“…MWCNTs have also been used in the catalytic liquid-phase oxidation of cumene with atmospheric oxygen in the presence of MWCNTs modified on the surface with silver nanocrystals by other authors [11]. The nanotubes were also used in the catalytic oxidation of phenol, nitrobenzene and aniline [12][13][14].…”

Section: Introductionmentioning

confidence: 99%

Carbon nanotubes catalysis in liquid-phase aerobic oxidation of hydrocarbons: Influence of nanotube impurities

Zeynalov

Allen

Salmanova

et al. 2019

Journal of Physics and Chemistry of Solids

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Pure carbon nanotubes (CNTs) have a high electron affinity and as such are able to actively absorb free radicals. This functional feature of CNTs leads to a linear chain breakage with the formation of inert spin adducts and effective inhibition of the oxidation process. However, there is a clear contradiction in this issue in the literature with the analysis of research results indicating that CNTs exhibit antioxidant activity mainly in polymeric materials, under conditions of diffusional restrictions for oxygen access. While, in the liquid-phase oxidation of hydrocarbons by CNTs (CNTs synthesised by the thermal catalytic pyrolysis of carbon-containing raw materials (CVD-process)), the CNTs enhance catalytic processes. In this study the aerobic liquid phase oxidation of cumene and initiated (by azobisisobutyronitrile) at low-temperature (333 K) in the presence of multi-walled carbon nanotubes (MWCNTs) obtained by thermal catalytic pyrolysis of cyclohexane (catalyst-ferrocene) has been undertaken. Kinetic analysis establishes that the catalysis of the oxidation process is associated with the presence of metal compounds in the structure of the MWCNTs. These metals are residues of metal catalysts remaining in the synthesis and in the process of pyrolysis. The metals are converted, as a rule, into metal carbides and are not easily removable by treatment with mineral acids. Thus, in the presence of metals in the composition of MWCNTs, interfering parallel reactions are observed with two processes running in parallel-MWCNTs + R• (RO 2 •) → •MWCNTs-R (RO 2) and ROOH + M @ MWCNTs → RO• radicals (RO 2 •). The branching of the chain processes involving hydroperoxides suppresses the route of attachment of alkyl and peroxide radicals to the carbon cage structure of the nanotubes and the reaction proceeds in an autocatalytic mode. Contradictory conclusions regarding the effect of CNTs on the chain processes in the oxidation of organic substances (hydrocarbons, polymers) that exist in the literature are attributed to the lack of control over the presence and nature of the metal containing impurities in the CNTs.

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Catalytic systems of cumene oxidation based on multiwalled carbon nanotubes

Cited by 10 publications

References 10 publications

Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal–Organic Frameworks Prepared by a Facile “Green” Aqueous Synthesis

Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal–Organic Frameworks Prepared by a Facile “Green” Aqueous Synthesis

Zeolite-Based Catalysis for Phenol Production

Carbon nanotubes catalysis in liquid-phase aerobic oxidation of hydrocarbons: Influence of nanotube impurities

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