Heterocyclic compounds from allyl alcohol over molecular sieves

Bezouhanova, C.; Titorenkova, Cvetomira V.; Chanev, Christo

doi:10.1016/s1381-1169(97)00233-1

Cited by 5 publications

(6 citation statements)

References 9 publications

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“…[3,144] Although coke formation and consequent catalyst deactivation in the glycerol dehydration reaction is a topic that still needs further investigation, several proposals have been discussed in the literature. [81,[146][147][148][149] In accordance with the previous discussion, the coke formation occurs through several types of concomitant reactions involving the reaction products obtained from glycerol conversion. The main reactions which lead to the coke formation, besides dehydration, are cracking (breaking the σ CÀ C bonds), condensation, hydrogenation, dehydrogenation, acetylation and aldol condensation.…”

Section: Coke Formation and Regeneration Of Oxide Catalysts On Glycer...supporting

confidence: 80%

Catalytic Conversion of Glycerol to Acetol and Acrolein Using Metal Oxides: Surface Reactions, Prospects and Challenges

Barbosa

Braga

2022

ChemCatChem

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Glycerol dehydration to acetol and acrolein is an interesting reaction pathway for conversion of biomass‐derived products. However, they undergo extensive deactivation due to coke deposition and sintering, requiring the design of stable catalysts. The oxides stand out due to their natural abundance, simple synthesis, low cost and tunable acidic, basic and redox properties. The different studies apply these oxides as pure phase, supported, mixed or doped. However, it is observed that despite the large number of applied oxides in glycerol conversion, few works describe in detail about more complex oxides such as ferrites, hexaferrites, perovskites, among others. This review reports different acid oxides in the glycerol dehydration to acetol and acrolein as well as basic and redox oxides, describing a historical perspective, showing the most important theoretical foundations of heterogeneous catalysis to comprehend surface reactions and mentioning the different possibilities to understanding the different reactional pathway, highlighting the proposal mechanisms that explain the participation of the different active sites on the surface reactions. Furthermore, the sequence of reactions which show the origin of the coke deposited on catalyst surface was presented, emphasizing the main challenges. The role of the Lewis and Brønsted acid‐base sites present in the metal oxides and their interactions on glycerol dehydration were described, providing a direction to design catalysts for selective dehydration reactions resistant against coke deposition and sintering.

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Section: Coke Formation and Regeneration Of Oxide Catalysts On Glycer...supporting

confidence: 80%

Catalytic Conversion of Glycerol to Acetol and Acrolein Using Metal Oxides: Surface Reactions, Prospects and Challenges

Barbosa

Braga

2022

ChemCatChem

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“…101 For example, heterocyclic compounds can be formed from allyl alcohol, which is in situ produced by a secondary hydrogenation reaction of acrolein. 29,102 The products are cyclic unsaturated and oxygenated compounds like phenol, dihydrofuran, cyclopentenone, and cyclohexanone. In the system of catalytic glycerol dehydration, all of these compounds could be responsible for coking.…”

Section: Formation Of Cokementioning

confidence: 99%

“…The carbon–carbon bonds can be formed by the following reactions: (1) aldol condensation of acrolein and acetaldehyde to form 3-hydroxy-1-valeraldehyde and 3-hydroxybutyraldehyde, (2) reductive coupling of aldehydes to form polyolefins, and (3) condensation of two acrolein molecules to give a C 6 H 8 O product (2-methyl-2,4-pentadienal) . For example, heterocyclic compounds can be formed from allyl alcohol, which is in situ produced by a secondary hydrogenation reaction of acrolein. , The products are cyclic unsaturated and oxygenated compounds like phenol, dihydrofuran, cyclopentenone, and cyclohexanone. In the system of catalytic glycerol dehydration, all of these compounds could be responsible for coking.…”

Section: Conditions Affecting Cokingmentioning

confidence: 99%

Coking of Catalysts in Catalytic Glycerol Dehydration to Acrolein

Jiang

Zhou

Tesser

et al. 2018

Ind. Eng. Chem. Res.

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Catalytic glycerol dehydration provides a sustainable route to produce acrolein because glycerol is a bioavailable platform chemical. However, in this process catalysts are rapidly deactivated due to coking. This paper examines and discusses recent insights into coking of catalysts during catalytic glycerol dehydration. The nature and location of coke and the rate of coking depend on feedstock, operating conditions, and the acidity and pore structure of the solid catalysts. Several methods have been suggested for inhibiting the coking and slowing the deactivation of catalyst, including (1) cofeeding of oxygen, (2) tuning of the pore size of the solid acid catalysts, (3) doping noble metals (Ru, Pt, Pd) into the solid acid catalysts, and (4) designing new reactors. The present methods for inhibiting coking are still unsatisfactory. The deactivated catalysts can be regenerated by removing coke. Nevertheless, the rapid deactivation of the regenerated catalyst remains problematic. The literature survey indicates that the exact chemical compositions of the coke on the catalyst during glycerol dehydration remain elusive. The thermodynamics, kinetics, and mechanism of coking need to be probed so as to advance the development of a catalyst with high activity, selectivity, and resistance to coking to put the catalytic glycerol dehydration into practice.

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“…For example, acrolein itself could be converted to many heavier products including higher aldehydes, olefins, heterocyclic and/or aromatic compounds by a complex reaction network including the reductive coupling, aldol condensation, Diels-Alder reaction, dehydration, and dehydrogenation as well as hydrogenation. 26,27…”

Section: Possible Reactions Involved In the Dehydration Of Glycerolmentioning

confidence: 99%

Sustainable production of acrolein: investigation of solid acid–base catalysts for gas-phase dehydration of glycerol

et al. 2007

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Synthesis of acrolein by catalytic gas-phase dehydration of biomass-derivate glycerol was studied over various solid catalysts with a wide range of acid-base properties. The catalyst acidity and basicity were measured, respectively, by n-butylamine and benzoic acid titration methods using Hammett indicators. The most effective acid strength for the selective dehydration of glycerol to form acrolein appeared between 28.2 ¡ H 0 ¡ 23.0, with which acrolein was produced at a selectivity of 60-70 mol%. The catalysts having very strong acid sites (H 0 ¡ 28.2) effected a lower acrolein selectivity (40-50 mol%) due to more severe coke deposition in the reaction. Solid acids holding medium strong and weak acid sites (23.0 ¡ H 0 ¡ +6.8) were found to be not selective for the acrolein production, the acrolein selectivity being less than 30 mol%. The mass specific catalytic rate for the acrolein production showed a general trend to increase with the fractional acidity at 28.2 ¡ H 0 ¡ 23.0. The catalytic data also suggest that Brønsted acid sites were advantageous over Lewis acid sites in catalyzing the selective synthesis of acrolein from glycerol dehydration. Solid base catalysts were shown not to be effective for acrolein production.

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Heterocyclic compounds from allyl alcohol over molecular sieves

Cited by 5 publications

References 9 publications

Catalytic Conversion of Glycerol to Acetol and Acrolein Using Metal Oxides: Surface Reactions, Prospects and Challenges

Catalytic Conversion of Glycerol to Acetol and Acrolein Using Metal Oxides: Surface Reactions, Prospects and Challenges

Coking of Catalysts in Catalytic Glycerol Dehydration to Acrolein

Sustainable production of acrolein: investigation of solid acid–base catalysts for gas-phase dehydration of glycerol

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