Cycloketone condensation catalyzed by zirconia: Origin of reactant selectivity

Wan, Mi Mi; Liang, Decheng; Wang, Li; Zhang, Xiangwen; Yang, Dong; Li, Guozhu

doi:10.1016/j.jcat.2018.02.021

Cited by 16 publications

(7 citation statements)

References 43 publications

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“…It must be pointed out that no liquid products are detected when FFL or CPO are fed individually, suggesting that, if any selfcondensation is taking place, the products obtained are solids. As the CPO self-condensation products are soluble in water [38], this self-condensation is discarded. These profiles, in addition to adsorption of both compounds, suggest a relevant FFL oligomerization, result justified by the long time required to obtain the stable FFL signal.…”

Section: Preliminary Test Based On Optimized Batch Conditionsmentioning

confidence: 99%

Optimization of the process conditions for minimizing the deactivation in the furfural-cyclopentanone aldol condensation in a continuous reactor

Cueto

Faba

Dı́az

et al. 2020

Applied Catalysis B: Environmental

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Section: Preliminary Test Based On Optimized Batch Conditionsmentioning

confidence: 99%

Optimization of the process conditions for minimizing the deactivation in the furfural-cyclopentanone aldol condensation in a continuous reactor

Cueto

Faba

Dı́az

et al. 2020

Applied Catalysis B: Environmental

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“…In the past few years, an increased interest for aldol reactions has been seen in the literature, with more researchers following the idea of tailoring specific catalytic materials depending on the reaction under study. − Kinetic isotope labeling experiments have shown evidence for a bifunctional mechanism on TiO 2 where base sites are thought to abstract hydrogen to form enolates that then nucleophilically attack the carbonyl group of another molecule that is activated (made more reactive) by an acid site . Bifunctional catalysts of various types have been proposed on theoretical or experimental grounds, and their intrinsic relationships with activity and selectivity measurements continue to be explored for the sake of further improving the chemical process. ,− Wang and Iglesia have recently published a study on the activity of aldol reactions over TiO 2 , building on the existing knowledge, and concluding that Lewis acid–base site pairs of modest acid–base strength and acid–base site distances are preferred for turning over aldol condensation …”

Section: Introductionmentioning

confidence: 99%

Coupling of Acetaldehyde to Crotonaldehyde on CeO_2–x(111): Bifunctional Mechanism and Role of Oxygen Vacancies

et al. 2018

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Selective C–C coupling of oxygenates is pertinent to the manufacture of fuel and chemical products from biomass and from derivatives of C1 compounds (i.e., oxygenates produced from methane and CO2). Here we report a combined experimental and theoretical study on the temperature-programmed reaction (TPR) of acetaldehyde (AcH) on a partially reduced CeO2–x (111) thin film surface. The experiments have been carried out under ultra-high-vacuum conditions without continuous gas exposure, allowing better isolation of active sites and reactive intermediates than in flow reaction conditions. AcH does not undergo aldol condensation in a typical TPR procedure, even though the enolate form of AcH (CH2CHO) is readily produced on CeO2–x (111) with oxygen vacancies. We find however that a tailored “double-ramp” TPR procedure is able to successfully produce an aldol adduct, crotonaldehyde (CrA). Using density functional theory calculations and microkinetic modeling we explore several possible C–C coupling pathways. We conclude that the double-ramp procedure allows surface oxygen vacancy dimers, stabilized by adsorbate occupation, to form dynamically during the TPR. The vacancy dimers in turn enable C–C coupling to occur between an enolate and an adjacent AcH molecule via a bifunctional enolate–keto mechanism that is distinct from conventional acid- or base-catalyzed aldol condensation reactions. The proposed mechanism indicates that CrA desorption is rate-limiting while C–C coupling is facile.

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“…Therefore, a C–C coupling reaction is necessary to produce jet fuel precursors. In the recent literature, NaOH, KOH, Mg–Al hydrotalcite (MgAl-HT), MgZrO 2 , Nb 2 O 5 , MgO, and ZrO 2 have been used as catalysts for the self-aldol condensation of cyclopentanone. Ionic liquids are a family of salts which exist as liquid state at room temperature.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Decaline-Type Thermal-Stable Jet Fuel Additives with Cycloketones

Wang

Tang

et al. 2019

ACS Sustainable Chem. Eng.

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Decalin is a jet fuel additive with high thermal stability and energy density. Herein, we reported a novel method for the preparation of decalin from cyclopentanone, a hemicellulose derived cycloketone. Ethanolamine acetate (EAOAc), an ionic liquid catalyst which can be derived from biomass, was first applied to the self-aldol condensation of cyclopentanone and demonstrated good activity for this reaction. After the optimization of reaction conditions, ∼83.5% carbon yield of 2-cyclopentylidenecyclopentanone was achieved over the EAOAc catalyst. The hydrodeoxygenation of 2-cyclopentylidenecyclopentanone over a physical mixture of Ru/C and H-β zeolite afforded bi(cyclopentane) which could be further isomerized to decalin. Among the screened catalysts, La-Y zeolite exhibited excellent performance for the isomerization process. According to the characterization results, the high activity of La-Y was rationalized by its large medium-strong acid amount and the appropriate ratio of Brønsted acid to Lewis acid. Analogously, branched decalins were synthesized with cyclohexanone using the same procedure.

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Cycloketone condensation catalyzed by zirconia: Origin of reactant selectivity

Cited by 16 publications

References 43 publications

Optimization of the process conditions for minimizing the deactivation in the furfural-cyclopentanone aldol condensation in a continuous reactor

Optimization of the process conditions for minimizing the deactivation in the furfural-cyclopentanone aldol condensation in a continuous reactor

Coupling of Acetaldehyde to Crotonaldehyde on CeO_2–x(111): Bifunctional Mechanism and Role of Oxygen Vacancies

Synthesis of Decaline-Type Thermal-Stable Jet Fuel Additives with Cycloketones

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Cycloketone condensation catalyzed by zirconia: Origin of reactant selectivity

Cited by 16 publications

References 43 publications

Optimization of the process conditions for minimizing the deactivation in the furfural-cyclopentanone aldol condensation in a continuous reactor

Optimization of the process conditions for minimizing the deactivation in the furfural-cyclopentanone aldol condensation in a continuous reactor

Coupling of Acetaldehyde to Crotonaldehyde on CeO2–x(111): Bifunctional Mechanism and Role of Oxygen Vacancies

Synthesis of Decaline-Type Thermal-Stable Jet Fuel Additives with Cycloketones

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Coupling of Acetaldehyde to Crotonaldehyde on CeO_2–x(111): Bifunctional Mechanism and Role of Oxygen Vacancies