Highly enhanced direct catalytic oxidation of cyclohexane to adipic acid with molecular oxygen: Dynamic collaboration between zeolite channel micro-environment and Au clusters

Zhang, Zhiyang; Hu, Mi; Gui, Qingfeng; Gu, Jing; Xu, Wenlong; Xiao, Qingbo; Huang, Wei

doi:10.1016/j.cej.2023.143501

Cited by 10 publications

(3 citation statements)

References 35 publications

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“…To explore in greater detail the radical species in this work, electron paramagnetic resonance (EPR) measurement was also carried out utilizing 5,5-dimethyl-1-pyrroline N-Oxide (DMPO) as a radical capture reagent. It is demonstrated in Figure 12 that when cyclohexane was utilized as a model substrate possessing C-H bonds, the main radical species were carbon-centered radicals (cyclohexyl radical, C 6 H 11 •), peroxide-centered radicals (cyclohexyl peroxide radical, C 6 H 11 OO•), and oxygen-centered radicals (cyclohexyl oxygen radical, C 6 H 11 O• and hydroxyl HO•), which is in good agreement with the radical species reported in relevant documents [1,11,22,66,67]. Secondly, in the determination of the major radical species, the activation of O 2 and the corresponding key intermediates were explored and verified, too.…”

Section: Mechanism Studysupporting

confidence: 87%

“…The functionalization of C-H bonds by means of oxidation utilizing molecular oxygen (O 2 ) is an extensively adopted strategy in the industrial utilization of fossil resources containing abundant hydrocarbons [1][2][3][4][5]. And, a troublesome issue in these important industrial processes is the deep conversion of partial oxidation products (POX-products) because POX-products, such as alcohols and ketones, are usually more reactive than substrates like cycloalkanes, alkanes, and alkyl aromatics [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

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Efficient Inhibition of Deep Conversion of Partial Oxidation Products in C-H Bonds’ Functionalization Utilizing O2 via Relay Catalysis of Dual Metalloporphyrins on Surface of Hybrid Silica Possessing Capacity for Product Exclusion

Zhang,

Feng,

et al. 2024

Biomimetics

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To inhibit the deep conversion of partial oxidation products (POX-products) in C-H bonds’ functionalization utilizing O2, 5-(4-(chloromethyl)phenyl)-10,15,20-tris(perfluorophenyl)porphyrin cobalt(II) and 5-(4-(chloromethyl)phenyl)-10,15,20-tris(perfluorophenyl)porphyrin copper(II) were immobilized on the surface of hybrid silica to conduct relay catalysis on the surface. Fluorocarbons with low polarity and heterogeneous catalysis were devised to decrease the convenient accessibility of polar POX-products to catalytic centers on the lower polar surface. Relay catalysis between Co and Cu was designed to utilize the oxidation intermediates alkyl hydroperoxides to transform more C-H bonds. Systematic characterizations were conducted to investigate the structure of catalytic materials and confirm their successful syntheses. Applied to C-H bond oxidation, not only deep conversion of POX-products was inhibited but also substrate conversion and POX-product selectivity were improved simultaneously. For cyclohexane oxidation, conversion was improved from 3.87% to 5.27% with selectivity from 84.8% to 92.3%, which was mainly attributed to the relay catalysis on the surface excluding products. The effects of the catalytic materials, product exclusion, relay catalysis, kinetic study, substrate scope, and reaction mechanism were also investigated. To our knowledge, a practical and novel strategy was presented to inhibit the deep conversion of POX-products and to achieve efficient and accurate oxidative functionalization of hydrocarbons. Also, a valuable protocol was provided to avoid over-reaction in other chemical transformations requiring high selectivity.

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Section: Mechanism Studysupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

Efficient Inhibition of Deep Conversion of Partial Oxidation Products in C-H Bonds’ Functionalization Utilizing O2 via Relay Catalysis of Dual Metalloporphyrins on Surface of Hybrid Silica Possessing Capacity for Product Exclusion

Zhang,

Feng,

et al. 2024

Biomimetics

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“…It plays a crucial role in various fields such as the chemical industry, organic synthesis, pharmaceuticals, and lubricant production. 4 The conventional synthesis processes of adipic acid mainly include cyclohexane oxidation 5 and cyclohexene hydration oxidation. 6 However, both synthesis routes have serious pollution problems.…”

Section: Introductionmentioning

confidence: 99%

Thermal Runaway Inhibition of Adipic Acid Green Synthesis Based on a Radical Chain Reaction Mechanism

Su,

Ni,

Cheng

et al. 2024

Org. Process Res. Dev.

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Adipic acid green synthesis is hazardous due to its highly exothermic nature and thermal instability of the raw material, hydrogen peroxide (H 2 O 2 ). In this work, an effective chemical method was proposed to inhibit the potential risk of reaction runaway based on a comprehensive study. Reaction species, including reactive intermediates, radicals were identified to establish the radical chain mechanism by various monitoring techniques, such as electron paramagnetic resonance (EPR). Meanwhile, the standard molar reaction enthalpies of each step were determined by theoretical calculations. Combined with the process hazard evaluation and reaction mechanism, the exothermic mechanism was proposed, indicating the heat release was mainly concentrated during the former stage (73 °C stage) of the reaction. Thus, a series of runaway inhibition experiments using radical inhibitor, 2,2,6,6-tetramethylpiperidine oxide (TEMPO) were conducted under different conditions. The results showed that the addition of TEMPO could reduce the maximum temperature, heat release, and maximum exothermic rate of the reaction. The addition of the radical inhibitor could quench all the radicals and terminate the reaction. Thus, the reaction runaway could be inhibited effectively.

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Metal coordination center mediated microenvironment regulation of cobalt sites on poly(ionic liquid)s enhance selective oxidation of cyclohexane conversion

Chen,

He,

et al. 2024

Chemical Engineering Journal

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Highly enhanced direct catalytic oxidation of cyclohexane to adipic acid with molecular oxygen: Dynamic collaboration between zeolite channel micro-environment and Au clusters

Cited by 10 publications

References 35 publications

Efficient Inhibition of Deep Conversion of Partial Oxidation Products in C-H Bonds’ Functionalization Utilizing O2 via Relay Catalysis of Dual Metalloporphyrins on Surface of Hybrid Silica Possessing Capacity for Product Exclusion

Efficient Inhibition of Deep Conversion of Partial Oxidation Products in C-H Bonds’ Functionalization Utilizing O2 via Relay Catalysis of Dual Metalloporphyrins on Surface of Hybrid Silica Possessing Capacity for Product Exclusion

Thermal Runaway Inhibition of Adipic Acid Green Synthesis Based on a Radical Chain Reaction Mechanism

Metal coordination center mediated microenvironment regulation of cobalt sites on poly(ionic liquid)s enhance selective oxidation of cyclohexane conversion

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