Morphological control of inverted MgO-SiO2 composite catalysts for efficient conversion of ethanol to 1,3-butadiene

Li, Shenxiao; Men, Yongfeng; Wang, Jinguo; Liu, Shuang; Wang, Xuefei; Ji, Fei; Chai, Shan-Shan; Song, Qiaoling

doi:10.1016/j.apcata.2019.03.007

Cited by 32 publications

(18 citation statements)

References 53 publications

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“…The Lebedev-process [3] where the ethanol is converted to BD over mixed oxide catalyst, like MgOÀ SiO 2 or ZnO-Al 2 O 3 , and the process of Ostromislensky [4] where a mixture of ethanol and acetaldehyde is reacted over alumina or clay catalysts. Recently, different oxides, mixed oxides, and zeolite supported catalysts, such as, SiO 2, [5][6][7][8] SiO 2 -ZrO 2, [9] zeolite Beta, [10] and MgOÀ SiO 2 [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] promoted with metals and/or metal oxides, such as oxides of Zn, [8,9,17,24,25,27] Ag, [10,27,28] Cu, [10,27] Au, [11] and Ga, [15,29] and metal combinations, like Zn-Hf, [5] Zn-Ta [7,30] and Zn-Zr [13,23,26] have been reported to be active in the ETB process.…”

Section: Introductionmentioning

confidence: 99%

MgO−SiO₂ Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

et al. 2020

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MgOÀ SiO 2 samples, having the composition of natural talc (NT), were obtained by co-precipitation (CP) and wet kneading (WK) methods. The materials were used as catalysts of the ethanolto-1,3-butadiene reaction. ZnO, Ga 2 O 3 and In 2 O 3 were tested as promoters. The catalyst WK gave the highest 1,3-Butadiene (BD) yield among the non-promoted catalysts because of the high specific surface area and strong basicity. Results suggested that over the neat WK catalyst the acetaldehyde coupling to crotonaldehyde was the rate-determining process step. Formation of crotyl alcohol intermediate was substantiated to proceed by the hydrogen transfer reaction between crotonaldehyde and ethanol. The crotyl alcohol intermediate becomes dehydrated to BD or, in a disproportionation side reaction, it forms crotonaldehyde and butanol. The promoter was found to increase the surface concentration of the reactant and reaction intermediates, thereby increases the rates of conversion and BD formation. The order of promoting efficiency was Zn > In > Ga.

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Section: Introductionmentioning

confidence: 99%

MgO−SiO₂ Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

et al. 2020

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“…For all the samples, the broad diffraction peaks at about 22° were attributed to amorphous silica [34]. Besides the characteristic diffraction of SiO 2 , for MgO/SiO 2 samples, the diffraction peaks at 42.7° and 62.2° can be well attributed to the (200) and (220) faces of poplycrystalline MgO species [35]. Whereas, there was only one broad peak at 42.7° owing to MgO in SiO 2 -MgO samples.…”

Section: Resultsmentioning

confidence: 99%

“…The one could be due to the highly dispersed MgO microcrystals confirmed by the XRD, which may expose more O LC 2− (LC = low coordination) sites at terraces, edges and corners [27]. On the other hand, the bridged O with enhanced electron cloud density in Si-O-Mg structure could also contribute to the surface basity [35].…”

Section: Resultsmentioning

confidence: 99%

“…Obviously, compared with CuO/SiO 2 catalysts, the introduction of Mg species did not have significant effect on the surface acidity of the catalysts. However, according to the previous studies, both of the doping of MgO species in to Cu/SiO 2 catalysts and the formation of Si-O-Mg structure could give rise to the increasement of the surface acidity of the catalysts [35,46]. At the present study, the reason for no obvious changes on the acidity of the catalysts may be due to the combined effects of the neutralizing by the surface basic sites and the covering by the copper species [46].…”

Section: Resultsmentioning

confidence: 99%

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Ethynylation of Formaldehyde over CuO/SiO2 Catalysts Modified by Mg Species: Effects of the Existential States of Mg Species

et al. 2019

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The highly effective catalytic synthesis of 1,4-butynediol (BD) from the Reppe process is a fascinating technology in modern chemical industry. In this work, we reported the effects of the existential states of Mg species in the CuO/silica-magnesia catalysts for the ethynylation of formaldehyde in a simulative slurry reactor. The physichemical properties of the supports and the corresponding catalysts were extensively characterized by various techniques. The experimental results indicated that the introduced Mg species in the form of MgO particles, MgO microcrystals, or Si-O-Mg structures effectively resulted in an abundance of medium-strong basic sites, which can synergize with the active Cu+ species, facilitate the activation of acetylene, and improve the ethynylation activity. For the CuO/MgO-SiO2 catalyst, the existence of Si-O-Mg structures strengthened the Cu–support interaction, which were beneficial to improving the dispersion and the valence stability of the active Cu+ species. The highly dispersed Cu+ species, its stable valence state, and the abundant medium-strong basic sites enhanced the synergistic effect significantly, leading to the superior activity and stability of CuO/MgO-SiO2. The insights into the role of the existential states of Mg species and the revelation of the synergistic effect between active Cu+ species and basic sites can provide theoretic guidance for future rational design of catalysts for the ethynylation reation.

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“…However, a high MgO content of 75 to 85 mol% is often recommended [21,27,29], even though lower MgO contents of 65 mol% have also been reported [30]. In recent times, the role of the multifunctionality of the catalyst systems used separately has also been studied more closely [31][32][33].…”

Section: Introductionmentioning

confidence: 99%

Studies on the Binary MgO/SiO2 Mixed Oxide Catalysts for the Conversion of Ethanol to 1,3-Butadiene

et al. 2020

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The demand for 1,3-butadiene, one of the most important raw materials in the rubber industry, is constantly increasing. The Lebedev process is a classical method of producing 1,3-butadiene from ethanol, which is to be optimized with regard to the mixed oxide catalysts used. In this work, the binary MgO/SiO2 solid system was tested with regard to its optimum chemical composition for the catalytic conversion of ethanol to 1,3-butadiene. Furthermore, novel mesoporous mixed oxides were prepared to investigate their textural, structural, and surface chemical properties as well as the catalytic activity. Nitrogen physisorption, scanning electron microscopy (SEM), and temperature-programmed ammonia desorption (NH3-TPD) measurements were carried out and evaluated. It was shown that the optimum yield of 1,3-butadiene is achieved by using MgO/SiO2 mixed oxide catalysts with 85–95 mol% MgO and not, as suggested by Lebedev, with 75 mol% MgO. The NH3-TPD measurements revealed that the maximum acid-site density is achieved with an equimolar up to magnesium-rich composition. During the synthesis of binary MgO/SiO2 solid systems based on mesoporous MgO, a thermally stable and ordered structure was formed in the autoclave, depending on the carbonate used and on the duration of the treatment.

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Morphological control of inverted MgO-SiO2 composite catalysts for efficient conversion of ethanol to 1,3-butadiene

Cited by 32 publications

References 53 publications

MgO−SiO₂ Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

MgO−SiO₂ Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

Ethynylation of Formaldehyde over CuO/SiO2 Catalysts Modified by Mg Species: Effects of the Existential States of Mg Species

Studies on the Binary MgO/SiO2 Mixed Oxide Catalysts for the Conversion of Ethanol to 1,3-Butadiene

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Morphological control of inverted MgO-SiO2 composite catalysts for efficient conversion of ethanol to 1,3-butadiene

Cited by 32 publications

References 53 publications

MgO−SiO2 Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

MgO−SiO2 Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

Ethynylation of Formaldehyde over CuO/SiO2 Catalysts Modified by Mg Species: Effects of the Existential States of Mg Species

Studies on the Binary MgO/SiO2 Mixed Oxide Catalysts for the Conversion of Ethanol to 1,3-Butadiene

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Product

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MgO−SiO₂ Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters

MgO−SiO₂ Catalysts for the Ethanol to Butadiene Reaction: The Effect of Lewis Acid Promoters