Vapor-phase self-aldol condensation of butanal over Ag-modified TiO 2

Sun, Daolai; Moriya, Shizuka; Yamada, Yoshio; Sato, Satoshi

doi:10.1016/j.apcata.2016.05.018

Cited by 24 publications

(12 citation statements)

References 40 publications

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“…In vapor-phase reactions over either acid or base catalysts, it is generally considered that the accumulation of carbonaceous compounds on the catalyst surface results in the catalytic deactivation [35]. In order to evaluate the coke formation, TG analyses of the used SiO 2 -Al 2 O 3 -CS, 10SiO 2 /Al 2 O 3 and 3Ag-10SiO 2 /Al 2 O 3 were performed in air.…”

Section: Characterization Of Catalyst Samplesmentioning

confidence: 99%

Vapor-phase dehydration of C4 unsaturated alcohols to 1,3-butadiene

Sun

Arai

Duan

et al. 2017

Applied Catalysis A: General

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Vapor-phase dehydration of C4 unsaturated alcohols such as 3-buten-1-ol, 2-buten-1-ol and 3-buten-2-ol were performed to produce 1,3-butadiene over various solid catalysts including ordinary solid acid catalysts such as Al 2 O 3 , SiO 2-Al 2 O 3 , and TiO 2 and basic rare earth metal oxides such as Yb 2 O 3 and CeO 2. In the reaction of 3-buten-1-ol, 1,3-butadiene could not be selectively produced because the acid catalysts decomposed 3-buten-1-ol into propylene. In contrast to the acid catalysts, CeO 2 inhibited the decomposition of 3-buten-1-ol and showed a relatively high performance for the formation of 1,3-butadiene. In the dehydration of 2-buten-1-ol and 3-buten-2-ol, however, acid catalysts were effective for the formation of 1,3-butadiene. Among the tested catalysts, commercial SiO 2-Al 2 O 3 showed a relatively high catalytic performance, although it deactivated rapidly. We prepared a series of SiO 2 /Al 2 O 3 catalysts by depositing SiO 2 species onto Al 2 O 3 support, and the SiO 2 /Al 2 O 3 with a SiO 2 content of 10 wt.% showed more stable catalytic activity than the commercial SiO 2-Al 2 O 3. Furthermore, modification of SiO 2 /Al 2 O 3 with Ag at a loading of 3-5 wt.% was found to be efficient for inhibiting the coke formation and improving the catalytic stability of SiO 2 /Al 2 O 3 in the dehydration of both 2-buten-1-ol and 3-buten-2-ol under hydrogen flow conditions.

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Section: Characterization Of Catalyst Samplesmentioning

confidence: 99%

Vapor-phase dehydration of C4 unsaturated alcohols to 1,3-butadiene

Sun

Arai

Duan

et al. 2017

Applied Catalysis A: General

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“…1‐butanol, 1,3‐butadiene, and diethylether) . Acetaldehyde, which is readily formed from ethanol via dehydrogenation, participates in multiple types of coupling reactions (e.g., aldol reaction, Guerbet reaction) that give larger chemical products, and the mechanisms and active surface species of these reactions have been investigated in detail over catalysts such as hydroxyapatite (HAP), metal oxides, and mixed metal oxides …”

Section: Introductionmentioning

confidence: 99%

“…1-butanol, 1,3-butadiene, and diethylether). [1,2,4] Acetaldehyde, which is readily formed from ethanol via dehydrogenation, participates in multiple types of coupling reactions (e.g.,a ldol reaction, Guerbet reaction) that give larger chemical products, and the mechanisms and active surface species of these reactions have been investigated in detail [5,6] over catalysts such as hydroxyapatite (HAP), [7][8][9][10][11] metal oxides, [8][9][10][11][12][13][14][15][16][17][18][19][20][21] and mixed metal oxides. [22][23][24][25] Such coupling reactions continue in as eries of steps that consumep rimary products and form largers pecies.…”

Section: Introductionmentioning

confidence: 99%

Formation Pathways toward 2‐ and 4‐Methylbenzaldehyde via Sequential Reactions from Acetaldehyde over Hydroxyapatite Catalyst

et al. 2017

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Condensation reactions of biomass derived C2 and C4 aldehydes form both ortho‐ and para‐tolualdehydes (2‐MB and 4‐MB, respectively). The complete reaction network and the detailed mechanisms, however, have not been fully described. Here, analysis of the products formed by sequential condensation reactions of acetaldehyde and 2‐butenal suggests that 2‐ and 4‐MB products form via aromatization of 2,4,6‐octatrienal and of highly reactive acyclic intermediate(s) formed via self‐addition of 2‐butenal, respectively. The exact positions at which C−C bonds form between C4 co‐reactants to create 4‐MB products were investigated by using reactant mixtures containing combinations of 2‐butenal, 2‐butenol, and 3‐methyl‐2‐butenal as model reactants. The last two reactants can form products that may be assigned to specific reaction pathways (not distinguishable during self‐addition of 2‐butenal) and also have decreased reactivity at specific carbon atoms. The analysis of the products suggests that 4‐MB species form via 2‐butenal self‐addition by nucleophilic attack of the α‐C to the carbonyl‐C. Additionally, Diels–Alder reactions (between C6 and C2 intermediates) do not contribute in any significant manner to the formation of 4‐MB. These findings complete the description of the reaction network that forms 2‐ and 4‐MB from acetaldehyde on hydroxyapatite.

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“…showed that butanal condensation could be carried out over Lewis acidic catalysts such as TiO 2 supported on SBA‐15 . Sun et al . revealed that pure TiO 2 is also active in butanal condensation to 2‐EN, while high catalyst stability is achieved by doping it with silver nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Hanna et al showed that butanal condensation could be carried out over Lewis acidic catalysts such as TiO 2 supported on SBA-15. [9] Sun et al [10] revealed that pure TiO 2 is also active in butanal condensation to 2-EN, while high catalyst stability is achieved by doping it with silver nanoparticles. According to Ordomsky et al [11] the main advantage of Lewis acids over solid bases is associated with a different condensation mechanism.…”

Section: Introductionmentioning

confidence: 99%

Selective Self‐Condensation of Butanal over Zr‐BEA Zeolites

2019

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Butanal conversion has been studied over Zr‐BEA zeolites with different amount of partially hydrolyzed open Zr‐sites and fully condensed closed sites. The kinetic study pointed that the main reaction pathway of butanal conversion involves its self‐condensation into 2‐ethyl‐2‐hexenal (2‐EN), the selectivity to 2‐EN being within 80–85 %. Besides, small amounts of 1‐butanol and butanoic acid are formed via Cannizzaro disproportionation of butanal. Secondary reactions include butanoic acid ketonization to 4‐heptanone and esterification to butyl butanoate and tandem hydrogenation/dehydration of 2‐EN into octadienes. A number of techniques, including FTIR spectroscopy of adsorbed CO, pyridine, 2,6‐di‐tert‐butylpyridine (DTBPy), TPD of isopropylamine and selective poisoning with DTBPy were applied for characterization of Zr‐sites and elucidation of their activity. Open Zr‐sites were found to be more active with respect to closed Zr‐sites in butanal condensation: the TOF values estimated at 433 K being 1.4 s−1 for open Zr‐sites and 0.6 s−1 for closed sites. On the contrary, selectivity into 2‐EN was similar for open and closed sites. The results point that Zr‐BEA catalysts with enhanced content of open sites are perspective catalysts for the selective synthesis of 2‐EN.

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Vapor-phase self-aldol condensation of butanal over Ag-modified TiO 2

Cited by 24 publications

References 40 publications

Vapor-phase dehydration of C4 unsaturated alcohols to 1,3-butadiene

Vapor-phase dehydration of C4 unsaturated alcohols to 1,3-butadiene

Formation Pathways toward 2‐ and 4‐Methylbenzaldehyde via Sequential Reactions from Acetaldehyde over Hydroxyapatite Catalyst

Selective Self‐Condensation of Butanal over Zr‐BEA Zeolites

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