Aldol condensation reactions of acetone and formaldehyde over vanadium phosphate catalysts: Comments on the acid–base properties

Tanner, R. J. N.; Gill, Philip; Wells, Richard; Bailie, Jillian E.; Kelly, Gordon; Jackson, S. David; Hutchings, Graham J.

doi:10.1039/b108794k

Cited by 23 publications

(31 citation statements)

References 52 publications

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“…Acetone can be considered as a prototype for aldol condensation . As a versatile electrophile in organic synthesis, formaldehyde shows a high activity in both aldol and Prins condensations .…”

Section: Introductionmentioning

confidence: 99%

“…Acetone can be considered as a prototype for aldol condensation. [35] As a versatile electrophile in organic synthesis, formaldehyde shows a high activity in both aldol and Prins condensations. [9,36,37] In the previous studies of aldol condensa-tion over the metal oxide catalysts, [9][10][11] only the α-H abstraction and the CÀ C coupling steps were extensively explored.…”

Section: Introductionmentioning

confidence: 99%

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Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO₂(101) Surface: A Theoretical Investigation

et al. 2020

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A mechanistic understanding of catalytic reactions at solid‐liquid interface is limited both experimentally and theoretically but attracts much interest. Using density functional theory calculations (DFT) and ab initio molecular dynamics (AIMD) simulations, we investigated the effect of liquid water on α‐H abstraction, C−C coupling, and dehydration steps of aldol condensation of formaldehyde and acetone on an anatase TiO2(101) surface. The existence of the aqueous phase lowered the Gibbs energy of activation of dehydration step pronouncedly from 187 to 74 kJ/mol through proton transfer mechanism, making the hydrogenation pathway more favorable in the aqueous phase. In contrast, a mixed route prevails in the vapor phase. This work provides insights into the effect of the bulk water through a proton transfer mechanism on the dehydrogenation, C−C coupling, and dehydration steps.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO₂(101) Surface: A Theoretical Investigation

et al. 2020

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“…37 The band at 982 cm −1 had been assigned to V O P vibrational mode while the additional two minor bands appearing at 1110 and 1151 cm −1 belongs to the P O stretching bonds of the VHP. 35 Other low intense bands assignable to VHP are noticeable at lower Raman region of 200-600 cm −1 . Some of these bands are also visible in the doped-VHP catalyst with different nanosized metal particles.…”

Section: Characterisation Of Catalyst Materialsmentioning

confidence: 98%

Catalytic Activity and Structure Properties of Doped VOHPO<SUB>4</SUB>·0.5H<SUB>2</SUB>O with Nanosized Ru, Au, Fe and Mn in Benzene Hydroxylation

Makgwane¹,

Ray²

2013

j. nanosci. nanotech.

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The promotional effect of nanosized Ru, Fe, Au, and Mn particles on VOHPO4 x 0.5H2O (VHP) catalytic properties was investigated in benzene hydroxylation reaction using hydrogen hydroperoxide (H2O2) as oxidant. Catalytic results indicated a profound effect of the nanoparticle dopants on VHP catalyst activity and products distribution. Amongst the promoted VHP catalysts, Au/VHP exhibited high catalytic effect with benzene conversion of 76% at a combined 85.5% selectivity toward the formation of phenol and hydroquinone achieved in 6 h under optimised reaction conditions. The extended scope application of nanosized doped Au-VHP showed to provide an effective catalyst for activation of the aromatic hydrocarbons C-H bonds into oxygenate derivatives. The catalyst could be re-used for several cycles with insignificant loss of activity. The doped nanosized Au-VHP catalyst provide a clean promising catalytic route based on heterogeneous catalysis for transformation of aromatics into value-added oxygenates.

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“…As stated in the Introduction, deactivation during decomposition of MBOH on basic zeolites could involve condensation of acetone, as was proposed earlier although the phenomenon and its extent were never analysed in running conditions. In fact, aldolic condensation of acetone on basic catalysts is a well-known reaction 9,10,[22][23][24] in which the first step involves the elimination of a proton by the basic site, giving an enolate that by reaction with a second acetone molecule gives diacetone alcohol (DAA). The latter can next be reversibly dehydrated to mesityl oxide (MSO) with production of a water molecule.…”

Section: Microgc Study Of Mboh Conversionmentioning

confidence: 99%

Mechanism and deactivation process of the conversion of methylbutynol on basic faujasite monitored by operando DRIFTS

Groust¹,

Costentin²,

Massiani³

2010

Phys. Chem. Chem. Phys.

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The successive steps occurring during conversion of methylbutynol (MBOH) on a basic NaX zeolite catalyst were characterized by combined micro-GC and operando DRIFT spectroscopy, associated to TPD-MS experiments. These techniques permit to reveal a very strong and fast initial decrease in MBOH consumption, associated to some water desorption and to a deficit in acetone that is a product formed together with acetylene, in agreement with the basic route. The origin of deactivation, the nature and reactivity of the adsorbed compounds and their relative strengths of adsorption are discussed on the basis of the evolution of the operando DRIFT spectra with time on stream and next upon keeping the used catalyst in static then under flowing N(2). The FTIR signatures of the three different modes of MBOH adsorption are determined and only the mode involving a zeolite acid-base pair is found reactive. Aldolic condensation is identified but solely to a minor extent in flowing conditions of the reaction whereas it is significantly enhanced in static. Thus, the apparent initial deactivation can be ascribed mainly to MBOH adsorption.

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Aldol condensation reactions of acetone and formaldehyde over vanadium phosphate catalysts: Comments on the acid–base properties

Cited by 23 publications

References 52 publications

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO₂(101) Surface: A Theoretical Investigation

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO₂(101) Surface: A Theoretical Investigation

Catalytic Activity and Structure Properties of Doped VOHPO<SUB>4</SUB>·0.5H<SUB>2</SUB>O with Nanosized Ru, Au, Fe and Mn in Benzene Hydroxylation

Mechanism and deactivation process of the conversion of methylbutynol on basic faujasite monitored by operando DRIFTS

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Aldol condensation reactions of acetone and formaldehyde over vanadium phosphate catalysts: Comments on the acid–base properties

Cited by 23 publications

References 52 publications

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO2(101) Surface: A Theoretical Investigation

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO2(101) Surface: A Theoretical Investigation

Catalytic Activity and Structure Properties of Doped VOHPO<SUB>4</SUB>·0.5H<SUB>2</SUB>O with Nanosized Ru, Au, Fe and Mn in Benzene Hydroxylation

Mechanism and deactivation process of the conversion of methylbutynol on basic faujasite monitored by operando DRIFTS

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Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO₂(101) Surface: A Theoretical Investigation

Aqueous Phase Aldol Condensation of Formaldehyde and Acetone on Anatase TiO₂(101) Surface: A Theoretical Investigation