- Preparation method of 2-butenol
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The invention discloses a preparation method of 2-butenol, which comprises the following steps of: reacting 2-butenol and isopropanol serving as reaction raw materials, aluminum isopropoxide serving as a catalyst I and metal chloride or metal oxide servin
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Paragraph 0014-0040
(2021/08/14)
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- Metal-doped mesoporous ZrO2catalyzed chemoselective synthesis of allylic alcohols from Meerwein-Ponndorf-Verley reduction of α,β-unsaturated aldehydes
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Meerwein-Ponndorf-Verley reduction (MPVr) is a sustainable route for the chemoselective transformation of α,β-unsaturated aldehydes. However, tailoring ZrO2 catalysts for improved surface-active sites and maximum performance in the MPV reaction is still a challenge. Here, we synthesized mesoporous zirconia (ZrO2) and metal-doped zirconia (M_ZrO2, M = Cr, Mn, Fe, and Ni). The incorporation of metal dopants into zirconia's crystal framework alters its physico-chemical properties such as surface area and total acidity-basicity. The prepared catalysts were evaluated in the MPVr using 2-propanol as a hydrogen donor under mild reaction conditions. The catalysts' remarkable reactivity depends mainly on their surface mesostructure's intrinsic properties rather than the specific surface area. Cr_ZrO2, which is stable and sustainable, presented superior activity and 100% selectivity to unsaturated alcohols. The synergistic effect between Cr and Zr species in the binary oxide facilitated the Lewis acidity-induced performance of the Cr_ZrO2 catalyst. Our work presents the first innovative application of a well-designed mesoporous Cr_ZrO2 in the green synthesis of unsaturated alcohols with exceptional reactivity. This journal is
- Akinnawo, Christianah Aarinola,Bingwa, Ndzondelelo,Meijboom, Reinout
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p. 7878 - 7892
(2021/05/13)
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- The roles of metal-promoter interface on liquid phase selective hydrogenation of crotonaldehyde over Ir-MoOx/BN catalysts
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A series of MoOx-promoted Ir/BN catalysts were tested for liquid phase selective hydrogenation of crotonaldehyde. The MoOx-promotion could significantly improve the reactivity up to 5-fold. Such improvement was mainly due to the form
- Jia, Aiping,Lu, Jiqing,Luo, Mengfei,Tang, Cen,Wen, Yang,Xu, Yumeng,Zhou, Fangru
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- Thermal Unequilibrium of PdSn Intermetallic Nanocatalysts: From In Situ Tailored Synthesis to Unexpected Hydrogenation Selectivity
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Effective control on chemoselectivity in the catalytic hydrogenation of C=O over C=C bonds is uncommon with Pd-based catalysts because of the favored adsorption of C=C bonds on Pd surface. Here we report a unique orthorhombic PdSn intermetallic phase with unprecedented chemoselectivity toward C=O hydrogenation. We observed the formation and metastability of this PdSn phase in situ. During a natural cooling process, the PdSn nanoparticles readily revert to the favored Pd3Sn2 phase. Instead, using a thermal quenching method, we prepared a pure-phase PdSn nanocatalyst. PdSn shows an >96 % selectivity toward hydrogenating C=O bonds of various α,β-unsaturated aldehydes, highest in reported Pd-based catalysts. Further study suggests that efficient quenching prevents the reversion from PdSn- to Pd3Sn2-structured surface, the key to the desired catalytic performance. Density functional theory calculations and analysis of reaction kinetics provide an explanation for the observed high selectivity.
- Chen, Minda,Dolge, Kevin,Gebre, Mebatsion,Heintz, Patrick,Huang, Wenyu,Jing, Dapeng,Lamkins, Andrew,Liu, Fudong,Ordonez, Claudio,Qi, Long,Shoemaker, Daniel P.,Wang, Bin,Yan, Yu,Zhang, Biying
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supporting information
p. 18309 - 18317
(2021/07/20)
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- Probing the Interface between Encapsulated Nanoparticles and Metal-Organic Frameworks for Catalytic Selectivity Control
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Encapsulating metal nanoparticles (NPs) in metal-organic frameworks (MOFs) to control catalytic selectivity has recently attracted great attention; however, an understanding of the NP-MOF interface is lacking. In this work, we used spectroscopy to investi
- Lo, Wei-Shang,Chou, Lien-Yang,Young, Allison P.,Ren, Chenhao,Goh, Tian Wei,Williams, Benjamin P.,Li, Yang,Chen, Sheng-Yu,Ismail, Mariam N.,Huang, Wenyu,Tsung, Chia-Kuang
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- Catalytic Asymmetric Allylic Substitution with Copper(I) Homoenolates Generated from Cyclopropanols
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By using copper(I) homoenolates as nucleophiles, which are generated through the ring-opening of 1-substituted cyclopropane-1-ols, a catalytic asymmetric allylic substitution with allyl phosphates is achieved in high to excellent yields with high enantioselectivity. Both 1-substituted cyclopropane-1-ols and allylic phosphates enjoy broad substrate scopes. Remarkably, various functional groups, such as ether, ester, tosylate, imide, alcohol, nitro, and carbamate are well tolerated. Moreover, the present method is nicely extended to the asymmetric construction of quaternary carbon centers. Some control experiments argue against a radical-based reaction mechanism and a catalytic cycle based on a two-electron process is proposed. Finally, the synthetic utilities of the product are showcased by means of the transformations of the terminal olefin group and the ketone group.
- Shi, Chang-Yun,Yin, Liang,Zhang, Qi,Zhou, Si-Wei
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supporting information
p. 26351 - 26356
(2021/11/09)
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- Vapor-phase dehydration of 1,4-butanediol to 1,3-butadiene over Y2Zr2O7 catalyst
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Vapor-phase catalytic dehydration of 1,4-butanediol (1,4-BDO) was investigated over Y2O3-ZrO2 catalysts. In the dehydration, 1,3-butadiene (BD) together with 3-buten-1-ol (3B1OL), tetrahydrofuran, and propylene was produced depending on the reaction conditions. In the dehydration over Y2O3-ZrO2 catalysts with different Y contents at 325°C, Y2Zr2O7 with an equimolar ratio of Y/Zr showed high selectivity to 3B1OL, an intermediate to BD. In the dehydration at 360°C, a BD yield higher than 90% was achieved over the Y2Zr2O7 calcined at 700°C throughout 10 h. In the dehydration of 3B1OL over Y2Zr2O7, however, the catalytic activity affected by the calcination temperature is roughly proportional to the specific surface area of the sample. The highest activity of Y2Zr2O7 calcined at 700 °C for the BD formation from 1,4-BDO is explained by the trade-off relation in the activities for the first-step dehydration of 1,4-BDO to 3B1OL and for the second-step dehydration of 3B1OL to BD. The higher reactivity of 3B1OL than saturated alcohols such as 1-butanol and 2-butanol suggests that the C=C double bond of 3B1OL induces an attractive interaction to anchor the catalyst surface and promotes the dehydration. A probable mechanism for the one-step dehydration of 1,4-BDO to BD was discussed.
- Matsuda, Asami,Matsumura, Yoshitaka,Sato, Satoshi,Yamada, Yasuhiro
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- Selective production of 1,3-butadiene from 1,3-butanediol over Y2Zr2O7 catalyst
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The vapor-phase dehydration of 1,3-butanediol (1,3-BDO) to produce 1,3-butadiene (BD) was evaluated over yttrium zirconate, which was prepared through a hydrothermal aging process. 1,3-BDO was initially dehydrated to three unsaturated alcohols, namely 3-buten-2-ol, 3-buten-1-ol, and 2-buten-1-ol, followed by the further dehydration to BD. The catalytic activity of yttrium zirconate was greatly dependent on the calcination temperature. Also, the reaction temperature was one of the important factors to produce BD efficiently. The selectivity to BD was increased with increasing reaction temperature up to 375°C, while coke formation resulted in catalyst deactivation together with by-product formation at higher temperatures. Yttrium zirconate catalyst calcined at 900°C showed a high BD yield of 95% at 375°C and 10 hr on stream.
- Matsuda, Asami,Matsumura, Yoshitaka,Sato, Satoshi,Yamada, Yasuhiro
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p. 1651 - 1658
(2021/07/21)
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- PROCESS FOR PRODUCING DIENES
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A process for producing a diene, preferably a conjugated diene, more preferably 1,3-butadiene, comprising dehydrating at least one alkenol in the presence of at least one catalytic material comprising at least one acid catalyst based on silica (SiO2) and alumina (AI2O3), preferably a silica-alumina (SiO2-Al2O3), said catalyst having an alumina content (Al2O3) lower than or equal to 12% by weight, preferably between 0.1% by weight and 10% by weight, with respect to the catalyst total weight, said alumina content being referred to the catalyst total weight without binder, and a pore modal diameter between 9 nm and 170 nm, preferably between 10 nm and 150 nm, still more preferably between 12 nm and 120 nm. Preferably, said alkenol can be obtained directly from biosynthetic processes, or by catalytic dehydration processes of at least one diol, preferably a butanediol, more preferably 1,3-butanediol, still more preferably bio-1,3-butanediol, deriving from biosynthetic processes. Preferably, said 1,3-butadiene is bio-1,3-butadiene.
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Page/Page column 30-34
(2021/06/26)
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- CoOx@Co Nanoparticle-based Catalyst for Efficient Selective Transfer Hydrogenation of α,β-Unsaturated Aldehydes
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Currently, developing simple and effective catalysts for selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols is challenging. Herein, an efficient CoOx-shell/Co-core structured nanoparticle catalyst is synthesized by a facile ultrasonic-assisted carbothermal reduction method. The resultant catalyst exhibits outstanding catalytic performance toward the selective transfer hydrogenation of a wide spectrum of α,β-unsaturated aldehydes into corresponding unsaturated alcohols with over 90 % selectivity. This is the simplest nonprecious metal catalyst to be reported for the selective hydrogenation of unsaturated aldehydes.
- Gong, Wanbing,Han, Miaomiao,Chen, Chun,Lin, Yue,Wang, Guozhong,Zhang, Haimin,Zhao, Huijun
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p. 1019 - 1024
(2019/12/27)
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- A tannin-derived zirconium-containing porous hybrid for efficient Meerwein-Ponndorf-Verley reduction under mild conditions
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Both the use of renewable natural sources to prepare catalytic materials and the Meerwein-Ponndorf-Verley (MPV) reduction for carbonyl compounds are very attractive topics in catalysis. In this study, tannins were simply assembled with zirconium in water for the scalable preparation of a heterogeneous zirconium-tannin hybrid catalyst (Zr-tannin). Various characterizations demonstrated the formation of robust porous inorganic-organic frameworks and strong Lewis acid-base sites in Zr-tannin. The cooperative effect of these acid-base sites and the abundant porosity endowed Zr-tannin with a remarkable catalytic performance for the MPV reduction of a broad range of carbonyl compounds to alcohols with 2-propanol under mild conditions. Moreover, Zr-tannin exhibited good recyclability for at least five reaction cycles. This novel strategy using tannins as the raw materials to construct heterogeneous catalytic materials may have a huge potential for green chemical synthesis due to low cost, nontoxicity, and sustainability.
- Leng, Yan,Shi, Langchen,Du, Shengyu,Jiang, Jiusheng,Jiang, Pingping
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p. 180 - 186
(2020/01/13)
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- Electrochemical Reduction of Carbon Dioxide to 1-Butanol on Oxide-Derived Copper
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The electroreduction of carbon dioxide using renewable electricity is an appealing strategy for the sustainable synthesis of chemicals and fuels. Extensive research has focused on the production of ethylene, ethanol and n-propanol, but more complex C4 molecules have been scarcely reported. Herein, we report the first direct electroreduction of CO2 to 1-butanol in alkaline electrolyte on Cu gas diffusion electrodes (Faradaic efficiency=0.056 %, j1-Butanol=?0.080 mA cm?2 at ?0.48 V vs. RHE) and elucidate its formation mechanism. Electrolysis of possible molecular intermediates, coupled with density functional theory, led us to propose that CO2 first electroreduces to acetaldehyde-a key C2 intermediate to 1-butanol. Acetaldehyde then undergoes a base-catalyzed aldol condensation to give crotonaldehyde via electrochemical promotion by the catalyst surface. Crotonaldehyde is subsequently electroreduced to butanal, and then to 1-butanol. In a broad context, our results point to the relevance of coupling chemical and electrochemical processes for the synthesis of higher molecular weight products from CO2.
- Chen, Stuart Tze-Jin,García-Muelas, Rodrigo,López, Núria,Martín, Antonio J.,Pérez-Ramírez, Javier,Pablo-García, Sergio,Peng, Yujie,Per, Edwin Yu Xuan,Ting, Louisa Rui Lin,Veenstra, Florentine L. P.,Yeo, Boon Siang
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supporting information
p. 21072 - 21079
(2020/09/11)
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- Method for liquid-phase catalytic selective hydrogenation of crotonaldehyde
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The invention relates to the field of chemical synthesis, and discloses a crotonaldehyde liquid-phase catalytic selective hydrogenation method, which comprises: carrying out a mixing reaction on ethanol and crotonaldehyde in the presence of a catalyst in an inert atmosphere under stirring under a crotonaldehyde liquid-phase catalytic selective hydrogenation condition to obtain a reaction product mixture, and separating out the catalyst to obtain the crotonaldehyde. Filtering to obtain crotonyl alcohol and 1, 1-diethoxyethane; the catalyst contains a carrier and a metal active component, an XPSmethod is adopted for characterization to obtain a metal inner-layer electron binding energy migration value delta E, delta E represents the difference between the inner-layer electron binding energyof the metal component in the catalyst and the binding energy of the metal oxide, and [delta]E is larger than 0.5 eV. According to the crotonaldehyde liquid-phase catalytic selective hydrogenation method, ideal selectivity and yield of crotonyl alcohol can be obtained, and acetal with high additional value can be obtained on the premise of sacrificing the selectivity of crotonyl alcohol as low aspossible, so that the product utilization rate is increased, the market competitiveness is enhanced, and the economic value is extremely high.
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Paragraph 0048-0074
(2020/12/29)
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- Synthesis of α,β- and β-Unsaturated Acids and Hydroxy Acids by Tandem Oxidation, Epoxidation, and Hydrolysis/Hydrogenation of Bioethanol Derivatives
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We report a reaction platform for the synthesis of three different high-value specialty chemical building blocks starting from bio-ethanol, which might have an important impact in the implementation of biorefineries. First, oxidative dehydrogenation of ethanol to acetaldehyde generates an aldehyde-containing stream active for the production of C4 aldehydes via base-catalyzed aldol-condensation. Then, the resulting C4 adduct is selectively converted into crotonic acid via catalytic aerobic oxidation (62 % yield). Using a sequential epoxidation and hydrogenation of crotonic acid leads to 29 % yield of β-hydroxy acid (3-hydroxybutanoic acid). By controlling the pH of the reaction media, it is possible to hydrolyze the oxirane moiety leading to 21 % yield of α,β-dihydroxy acid (2,3-dihydroxybutanoic acid). Crotonic acid, 3-hydroxybutanoic acid, and 2,3-dihydroxybutanoic acid are archetypal specialty chemicals used in the synthesis of polyvinyl-co-unsaturated acids resins, pharmaceutics, and bio-degradable/ -compatible polymers, respectively.
- Faria, Jimmy,Komarneni, Mallik R.,Li, Gengnan,Pham, Tu,Resasco, Daniel E.,Ruiz, Maria P.,Santhanaraj, Daniel
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supporting information
p. 7456 - 7460
(2020/03/23)
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- PROCESS FOR BIO-1,3-BUTANEDIOL PURIFICATION FROM A FERMENTATION BROTH
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Process for bio-1,3-butanediol purification from a fermentation broth comprising the following steps: (a) subjecting the fermentation broth to separation; (b) subjecting the product obtained in step (a) to treatment with ion-exchange resins; (c) subjecting the product obtained in step (b) to a first evaporation; (d) subjecting the product obtained in step (c) to a second evaporation; (e) subjecting the product obtained in step (d) to a third evaporation, obtaining purified bio-1,3-butanediol. Said purified bio-1,3-butanediol may advantageously be used for the production of bio- 1,3-butadiene, which in turn may advantageously be used as a monomer or as an intermediate in the production of elastomers and (co)polymers.
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Page/Page column 45; 47-49
(2020/04/25)
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- Promoted chemoselective crotonaldehyde hydrogenation on zirconia-doped SiO2 supported Ag catalysts: Interfacial catalysis over ternary Ag–ZrO2–SiO2 interfaces
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In gas-phase chemoselective hydrogenation of crotonaldehyde on Ag-based catalysts, zirconia doping on silica supports was found to improve catalytic performance in terms of unsaturated alcohol selectivity, hydrogenation activity, and stability. The surface modification of silica by zirconia doping favors the fine dispersion of Ag species due to the enhanced quantity and strength of surface acid sites, which enable construction of abundant catalytic sites effective for C[dbnd]O bond hydrogenation. High crotyl alcohol selectivity, exceeding 80%, and significant inhibition of monohydrogenation on the C[dbnd]C bond were observed on the optimal Ag/Zr–SiO2 catalyst. Dynamic O2 chemisorption measurement revealed that the pure Ag powders did not chemisorb O2 irreversibly under 323 K, but SiO2 or Zr–SiO2 supported Ag catalysts did. The amounts of Ag active for O2 chemisorption, which are at least one order of magnitude lower than that of surface Ag derived from TEM and XRD characterizations, match well with the perimeter interface Ag of hemispherical particles. A strong correlation between hydrogenation activity and O2 uptake on those Ag/SiO2 and Ag/Zr–SiO2 catalysts with different Ag dispersions and deactivation degrees was observed, implying that the effective catalytic sites for crotonaldehyde chemoselective hydrogenation may originate from accessible interface sites with unique redox properties. Catalyst induction and deactivation were observed on both Ag/SiO2 and Ag/Zr–SiO2 catalysts in real catalytic operation. Changes in metal stable interface structure, rather than metal aggregation and coagulation, are assumed to be the main cause of irreversible catalyst deactivation, because the apparent Ag particle sizes changed slightly, but the oxygen chemisorption ability deteriorated considerably. Electropositive Ag sites interacting with neighboring oxygen from oxide supports at the ternary Ag–ZrO2–SiO2 interface are proposed to account for highly selective C[dbnd]O bond hydrogenation to produce the desired unsaturated alcohol.
- Lin, Haiqiang,Qu, Hongyan,Chen, Weikun,Xu, Kang,Zheng, Jianwei,Duan, Xinping,Zhai, Hesheng,Yuan, Youzhu
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- An On-Demand, Selective Hydrogenation Catalysis over Pt?Fe Nanocatalysts under Ambient Condition
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The selective hydrogenation of organic compounds with multiple unsaturated bonds is of significant for fine chemicals, while simultaneously achieving high selectivities of different potential products is still great challenge. Herein, we have successfully designed a nanocatalysis system, which can serve as a control switch of selective α, β-unsaturated aldehydes hydrogenation towards potential products in a highly on-demand fashion. We demonstrate that the PtFe nanospheres (NSs) represent excellent selectivity (>92.8 %) to unsaturated alcohols with high conversion (>99.7 %), due to the higher electron density of the active Pt atoms. When introducing AlCl3, the selectivity of saturated aldehydes enhances to 97.1 % at 95.8 % conversion, owing to synergy between PtFe NSs and AlCl3. Finally, the PtFe?A NSs generated by etching away the Fe can promote the selectivity saturated alcohols (>99.7 %) with the highest activity, on account of more exposed active sites after the chemical etching. Significantly, the developed nanocatalysis system can also exhibit high activity/selectivity for other typical α, β-unsaturated aldehydes as well as excellent stability after consecutive reactions. This work provides a guideline for the rational design highly active and selective Pt-based nanocatalyst.
- Yang, Chengyong,Bai, Shuxing,Feng, Yonggang,Huang, Xiaoqing
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p. 2265 - 2269
(2019/04/13)
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- Hydrogenation of Cyclohexene in Aqueous Solvent Mixture Over a Sustainable Recyclable Catalyst Comprising Palladium and Monolacunary Silicotungstate Anchored to MCM-41
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An efficient, highly stable, and ligand-free catalyst consisting of Pd and monolacunary silicotungstate anchored to MCM-41 was synthesized and characterized by various techniques. The synthesized catalyst was used for the hydrogenation reaction of cyclohe
- Patel, Anjali,Patel, Anish,Narkhede, Nilesh
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p. 423 - 429
(2019/01/24)
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- Structure-Reactivity Relations in Ruthenium Catalysed Furfural Hydrogenation
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Furfural is an abundant and low-cost bio-derived platform chemical, obtained by xylose dehydration, and an important precursor to furfuryl alcohol and furan resins. The liquid phase selective hydrogenation of furfural to furfuryl alcohol was systematically investigated over silica supported Ru nanoparticles to elucidate structure-reactivity relations and obtain mechanistic insight. Furfural hydrogenation to furfuryl alcohol is weakly structure sensitive for Ru nanoparticles spanning 2 to 25 nm, and the dominant reaction pathway reaching 95 % selectivity under our conditions (2 and 100–165 °C). In contrast, furfural decarbonylation to furan exhibits a strong structure sensitivity, being favoured over sub-10 nm particles. Increasing pH2 from 10 to 25 bar resulted in a modest increase in C=O hydrogenation, while higher temperatures promoted ring-opening of furfuryl alcohol.
- Durndell, Lee J.,Zou, Guchu,Shangguan, Wenfeng,Lee, Adam F.,Wilson, Karen
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p. 3927 - 3932
(2019/05/29)
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- The selective hydrogenation of furfural over intermetallic compounds with outstanding catalytic performance
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The selective hydrogenation of furfural (a biomass-derived platform compound, CO versus CC) is an important reaction for the production of chemical intermediates widely used in the polymer industry. Herein, we report three non-precious intermetallic compounds (IMCs) (Ni3Sn1, Ni3Sn2 and Ni3Sn4) derived from a layered double hydroxide (LDH) precursor, which are characterized by a highly uniform dispersion of IMC nanoparticles and display surprisingly improved catalytic performance toward the selective hydrogenation of furfural (CO) to furfuryl alcohol. In particular, the Ni3Sn2 IMC shows optimal catalytic behavior (conversion: 100%; selectivity: 99%), which exceeds that of reported non-precious metal catalysts and is even comparable to that of noble metal catalysts (e.g., Au, Pd and Pt). A combinative investigation based on in situ FT-IR, XANES and Bader charge studies verifies electron transfer from Sn to Ni, facilitating the activation of adsorption of the CO bond on the Ni top site, whilst inhibiting the adsorption of CC. Both experimental studies (in situ FT-IR and catalytic evaluations) and theoretical calculations (DFT calculations and microkinetic modeling) reveal a vertical adsorption configuration of furfural molecules over the Ni3Sn2 IMC, followed by the first hydrogenation at the carbon atom (the rate-determining step) and the second hydrogenation at the oxygen atom. This detailed study of the structure-selectivity relationship is substantiated by virtue of establishing the adsorption configuration of the substrate and the reaction pathway, which paves the way for the rational design and development of high-efficiency heterogeneous catalysts for selective hydrogenation reactions.
- Yang, Yusen,Chen, Lifang,Chen, Yudi,Liu, Wei,Feng, Haisong,Wang, Bin,Zhang, Xin,Wei, Min
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supporting information
p. 5352 - 5362
(2019/10/11)
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- Selective C=C Hydrogenation of Unsaturated Hydrocarbons in Neat Water Over Stabilized Palladium Nanoparticles Via Supported 12-Tungstophosphoric Acid
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Stabilized Pd(0) nanoparticles by supported 12-tungstophosphoric acid (Pd(0)-TPA/ZrO2) was explored as a sustainable recyclable catalyst for selective C=C hydrogenation of cyclohexene and crotonaldehyde. The catalyst shows an outstanding performance [catalyst to substrate ratio (1:1.31 × 104)] towards high conversion as well as 100% selectivity of the desired product with high turnover number (> 10,000) and turnover frequency (> 2600?h-1) for both the systems. The use of neat water as a solvent and mild reaction conditions makes the present system environmentally benign and green. Moreover, the catalyst could be recovered and reused up to five cycles without any significant loss in their conversion as well as selectivity. The viability of the catalyst was evaluated towards different aromatic as well as aliphatic arenes and found to be excellent in all the cases. The obtained selectivity, especially butyraldehyde, was correlated with the nature of the catalyst as well as solvent and based on the study, a plausible mechanism for both the reactions was also proposed. Graphical Abstract: [Figure not available: see fulltext.].
- Patel, Anish,Patel, Anjali
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p. 1476 - 1485
(2019/04/25)
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- In situ DRIFTS for the mechanistic studies of 1,4-butanediol dehydration over Yb/Zr catalysts
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To study the effect of acid-base properties of catalysts on 1,4-butanediol (BDO) dehydration to 3-buten-1-ol (BTO), Yb/Zr catalysts with different Yb content were synthesized by a wet impregnation method. The texture property, crystalline form and surface
- Mi, Rongli,Hu, Zhun,Yang, Bolun
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p. 138 - 151
(2019/01/04)
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- Efficient conversion of ethanol to 1-butanol and C5-C9 alcohols over calcium carbide
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Production of 1-butanol or alcohols with 4-9 carbon atoms (C4-C9 alcohols) from widely available bio-ethanol has attracted much interest in recent years in academia and industry of renewable chemicals and liquid fuels. This work discloses for the first time that calcium carbide (CaC2) has a superior catalytic activity in condensation of ethanol to C4-C9 alcohols at 275-300 °C. The 1-butanol yield reached up to 24.5% with ethanol conversion of 62.4% at the optimized conditions. The by-products are mainly alcohols with 5-9 carbons besides 2-butanol, and the total yield of all the alcohols reached up to 56.3%. The reaction route was investigated through controlled experiments and quantitative analysis of the products. Results indicated that two reaction routes, aldol-condensation and self-condensation, took place simultaneously. The aldol-condensation route involves coupling of ethanol with acetaldehyde (formed from ethanol dehydrogenation) to form 2-butenol, which is subsequently hydrogenated to 1-butanol. The alkynyl moiety in CaC2 plays an important role in the catalytic pathways of both routes and affords the good activity of CaC2. CaC2 is converted to acetylene [C2H2] and calcium hydroxide [Ca(OH)2] simultaneously by the H2O that was generated from the condensation of alcohols.
- Wang, Dong,Liu, Zhenyu,Liu, Qingya
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p. 18941 - 18948
(2019/07/04)
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- Synthesis of the C1-C12 Fragment of Calyculin C
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Calyculins are a class of highly cytotoxic metabolites originally isolated from the marine sponge Discodermia calyx. To date, a total of twelve different calyculins (A-J) and calyculinamides (A, B and F) have been described, the most abundant (in D. calyx
- Konstantinova, Olga V.,Koskinen, Ari M.P.
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p. 285 - 295
(2019/01/04)
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- Multicomponent Pt-Based Zigzag Nanowires as Selectivity Controllers for Selective Hydrogenation Reactions
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The selective hydrogenation of α, β-unsaturated aldehyde is an extremely important transformation, while developing efficient catalysts with desirable selectivity to highly value-added products is challenging, mainly due to the coexistence of two conjugated unsaturated functional groups. Herein, we report that a series of Pt-based zigzag nanowires (ZNWs) can be adopted as selectivity controllers for α, β-unsaturated aldehyde hydrogenation, where the excellent unsaturated alcohol (UOL) selectivity (>95%) and high saturated aldehyde (SA) selectivity (>94%) are achieved on PtFe ZNWs and PtFeNi ZNWs+AlCl3, respectively. The excellent UOL selectivity of PtFe ZNWs is attributed to the lower electron density of the surface Pt atoms, while the high SA selectivity of PtFeNi ZNWs+AlCl3 is due to synergy between PtFeNi ZNWs and AlCl3, highlighting the importance of Pt-based NWs with precisely controlled surface and composition for catalysis and beyond.
- Bai, Shuxing,Bu, Lingzheng,Shao, Qi,Zhu, Xing,Huang, Xiaoqing
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supporting information
p. 8384 - 8387
(2018/06/29)
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- Three-Dimensionally Hierarchical Pt/C Nanocomposite with Ultra-High Dispersion of Pt Nanoparticles as a Highly Efficient Catalyst for Chemoselective Cinnamaldehyde Hydrogenation
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A monolithic carbon-supported Pt nanocomposite with an interconnected three-dimensionally hierarchical porous carbon framework and ultra-high dispersion of Pt nanoparticles (Pt/3DHPC) is synthesized by using an effective “liquid phase impregnation template” strategy. The obtained Pt/3DHPC possesses rich mesoporosity and a low amount of oxygen-containing functional groups, which notably improve the accessible internal surface area of macropores, number of active Pt sites, and electron transfer ability. When used as a catalyst for the selective cinnamaldehyde (CMA) hydrogenation towards cinnamyl alcohol (CMO), Pt/3DHPC exhibits high CMA conversion (92.7 %) and CMO selectivity (91.1 %) at 1 h reaction time, and the corresponding activity (1553.7 h?1) greatly surpasses not only the single-sized mesoporous carbon and microporous activated carbon-supported counterparts but also the previously reported Pt catalysts dispersed on other forms of carbon. Furthermore, Pt/3DHPC can be reused at least fifteen times without pronounced decay owing to the strong interaction between Pt and carbon. The present work demonstrates the validity of multiscale control in carbon-supported Pt catalysts by overall consideration of the mass transportation, and the accessibility, quantity, and capability of active sites towards chemoselective hydrogenation of CMA, which is expected to be extended to other catalysis-related processes.
- Hu, Duo,Fan, Wenqian,Liu, Zhi,Li, Ling
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p. 779 - 788
(2018/01/04)
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- Synthesis of bimetallic SnPt-nanoparticle catalysts for chemoselective hydrogenation of crotonaldehyde: Relationship between SnxPty alloy phase and catalytic performance
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Bimetallic SnPt-nanoparticle (SnPt-NP) catalysts with several types of SnxPty alloy structures were prepared using a polyalcohol reduction process; the catalytic behavior of each SnxPty alloy phase toward the selective hydrogenation of unsaturated aldehydes to the corresponding unsaturated alcohols was elucidated. Atomic absorption spectroscopy (AAS) and transmission electron microscopy (TEM) indicate that SnPt-NP catalysts with various Sn/Pt atomic ratios can be successfully prepared by a polyalcohol reduction process using Pt(acac)2 and Sn(AcO)2 as the metal precursors. X-ray diffraction (XRD) results reveal that the Sn1Pt3, Sn1Pt1, and Sn2Pt1 alloy phases are formed through control of the Sn/Pt atomic ratio of the starting mixture during preparation. The Sn1Pt3 alloy phase enhanced the hydrogenation of both the C[dbnd]C and C[dbnd]O bonds during the selective hydrogenation of crotonaldehyde. When only Sn1Pt1 alloy phases (Sn/Pt = 1.40), accompanying with separated Sn phase, were formed in the SnPt-NP catalysts, the highest unsaturated alcohol (UOL) selectivity (71.5% at 37.6% conversion) was observed. The formation of the Sn2Pt1 alloy phase led to decreased UOL selectivity. We suggest that the Sn1Pt1 alloy phase is an effective bimetallic SnPt hydrogenation catalyst for the selective formation of unsaturated alcohols.
- Taniya, Keita,Yu, Chih Hao,Takado, Hiromu,Hara, Taiki,Okemoto, Atsushi,Horie, Takafumi,Ichihashi, Yuichi,Tsang, Shik Chi,Nishiyama, Satoru
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p. 241 - 248
(2018/01/01)
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- Gold cluster catalyst for efficiently catalyzing selective hydrogenation of unsaturated aldehyde ketone to produce unsaturated alcohol
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The invention relates to a gold cluster catalyst for efficiently catalyzing selective hydrogenation of unsaturated aldehyde ketone to produce unsaturated alcohol. A gold cluster protected by a mercapto group is impregnated on different carriers, and the o
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Page/Page column 10
(2018/04/21)
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- Highly Networked Platinum–Tin Nanowires as Highly Active and Selective Catalysts towards the Semihydrogenation of Unsaturated Aldehydes
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The selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols is an important process for many industrial applications, whereas the realization of excellent conversion efficiency and selectivity remains a significant challenge. Herein, we report the preparation of a class of networked Pt–Sn nanowires (Pt–Sn NWs) for the selective hydrogenation of unsaturated aldehydes to the desired unsaturated alcohols. The optimized Pt1.5Sn NWs delivered a high conversion efficiency (98.1 %) for the hydrogenation of cinnamaldehyde (CAL) and excellent selectivity to cinnamyl alcohol (COL) (90.6 %); thus, they outperformed Pt1.5Sn nanoparticles (NPs) as well as Pt NPs. The high performance of the Pt1.5Sn NWs was expanded to the hydrogenation of other α,β-unsaturated aldehydes. X-ray photoelectron spectroscopy revealed that a high ratio of metallic Pt in the Pt1.5Sn NWs boosted the conversion of CAL and that a high Sn content favored the hydrogenation of the C=O bond, both of which lead to excellent activity and selectivity.
- Zhu, Meiwu,Huang, Bin,Shao, Qi,Pi, Yecan,Qian, Yong,Huang, Xiaoqing
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p. 3214 - 3218
(2018/08/24)
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- Rhodium-Catalyzed Synthesis of α,β-Unsaturated Ketones through Sequential C-C Coupling and Redox Isomerization
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A novel Rh(I)-catalyzed sequential C-C coupling and redox isomerization between allylic alcohols and 1,3-dienes has been accomplished. This versatile protocol provides expeditious access to a broad range of polysubstituted α,β-unsaturated ketones with excellent atom economy and regioselectivity.
- Li, Hong-Shuang,Guo, Guili,Zhang, Rui-Ze,Li, Fei
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supporting information
p. 5040 - 5043
(2018/08/24)
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- Selective production of 1,3-butadiene in the dehydration of 1,4-butanediol over rare earth oxides
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Vapor-phase dehydration of 1,4-butanediol and 3-buten-1-ol to produce 1,3-butadiene was investigated over rare earth oxides such as Lu2O3, Yb2O3, Tm2O3, Er2O3, and Sc1.0Yb1.0O3. In the dehydration of 3-buten-1-ol, heavy rare earth oxides such as Lu2O3, Yb2O3, and Er2O3 showed high catalytic performance for the selective formation of 1,3-butadiene with producing small amount of propylene whereas acidic catalysts such as alumina decomposed 3-buten-1-ol into propylene. In particular, over Yb2O3 calcined at 800 °C, 3-buten-1-ol was converted with a yield of 1,3-butadiene higher than 95% at 340 °C. In the dehydration of 1,4-butanediol, furthermore, we developed an efficient catalytic system: 1,3-butadiene was produced via an intermediate, 3-buten-1-ol, over Yb2O3 with an excellent yield of 96% at 360 °C and a high contact time of 2.26 h. Yb2O3 successfully inhibited the major side reaction such as decomposition of 3-buten-1-ol to propylene and provided the selective production of 1,3-butadiene from 1,4-butanediol.
- Wang, Yuchao,Sun, Daolai,Yamada, Yasuhiro,Sato, Satoshi
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- Aldol condensation among acetaldehyde and ethanol reactants on TiO2: Experimental evidence for the kinetically relevant nucleophilic attack of enolates
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Combinations of rate measurements as functions of reactant pressures, in situ infrared spectroscopy, comparisons of kinetic isotope effects, and rate inhibition effects provide experimental evidence that aldol condensation of acetaldehyde proceeds by kinetically relevant nucleophilic attack of a reactive enolate upon an acetaldehyde molecule over anatase TiO2. Steady-state turnover rates of aldol condensation measured as a function of the pressures of C2H4O, C2H5OH, H2O, and H2 between 503 K and 537 K show that rates reflect a second order dependence on C2H4O pressure and an inverse second order dependence on the C2H5OH pressure at the lowest C2H4O-to-C2H5OH ratios. Infrared spectra obtained in situ show that the exposed cationic Ti-atoms that facilitate aldol addition on TiO2 surfaces are saturated with C2H5OH? species and C2H4O? coverages are much smaller. In addition, aldol rates increase when C2D4O replaces C2H4O as a reactant, which likely reflects an inverse, secondary isotope effect caused by rehybridization of C-atoms at the transition state that forms a C–C bond between two reactive intermediates derived from acetaldehyde. These results suggest that the kinetically relevant step is a bimolecular surface reaction, specifically the nucleophilic attack of an enolate onto a vicinal C2H4O? species. This conclusion is consistent also with aldol condensation rates that decrease with an inverse second order dependence on pyridine (C5H5N) pressure, because C5H5N displaces C2H4O from the two Lewis acid sites involved in the kinetically relevant step (confirmed by in situ FTIR). Comparisons to recent reports on the mechanism of this reaction on anatase TiO2 indicate that the presence of high coverages of C2H5OH? causes nucleophilic attack to become the kinetically relevant step by significantly reducing the number of enolate-acetaldehyde reactant pairs upon the surface.
- Zhang, Hongbo,Ibrahim, Malek Y.S.,Flaherty, David W.
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p. 290 - 302
(2018/04/02)
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- DEHYDRATION OF DIOLS
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Provided is a method for producing an alkene. The method comprises a step of converting a compound (I) comprising at least two hydroxyl functions into a compound (II) comprising at least two alkenyl functions with cerium oxide particles as catalyst. It notably permits the conversion of 1,3-butanediol,1,4-butanediol into butadiene.
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Page/Page column 16; 17
(2018/03/25)
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- C(alkenyl)-H Activation via Six-Membered Palladacycles: Catalytic 1,3-Diene Synthesis
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A catalytic method to prepare highly substituted 1,3-dienes from two different alkenes is described using a directed, palladium(II)-mediated C(alkenyl)-H activation strategy. The transformation exhibits broad scope across three synthetically useful substrate classes masked with suitable bidentate auxiliaries (4-pentenoic acids, allylic alcohols, and bishomoallylic amines) and tolerates internal nonconjugated alkenes, which have traditionally been a challenging class of substrates in this type of chemistry. Catalytic turnover is enabled by either MnO2 as the stoichiometric oxidant or co-catalytic Co(OAc)2 and O2 (1 atm). Experimental and computational studies were performed to elucidate the preference for C(alkenyl)-H activation over other potential pathways. As part of this effort, a structurally unique alkenylpalladium(II) dimer was isolated and characterized.
- Liu, Mingyu,Yang, Pusu,Karunananda, Malkanthi K.,Wang, Yanyan,Liu, Peng,Engle, Keary M.
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supporting information
p. 5805 - 5813
(2018/05/14)
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- Novel method for preparing butanol by catalyzing ethanol condensation by virtue of manganese
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The invention discloses a novel method for preparing butanol by catalyzing ethanol condensation by virtue of manganese. A manganese catalyst adopted in the method is a manganese complex shown in a formula I, a formula II, a formula III or a formula IV. Based on the manganese complex, the invention provides a method for preparing butanol through ethanol coupling based on catalysis of cheap manganese metal, high catalytic activity (TON=114120, wherein TOF of early 12h is 3078/h) and 92% butanol selectivity (figure 1) are shown. The method disclosed by the invention has the advantages that biomass resources are efficiently utilized, and especially an important technical support and theoretical guidance are provided for production of high-quality biofuel, catalytic activation and transformation of a biomass platform compound and design of a corresponding cheap and efficient catalyst.
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Paragraph 0149-0151
(2017/12/30)
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- Insight into the structure evolution and the associated catalytic behavior of highly dispersed Pt and PtSn catalysts supported on La2O2CO3 nanorods
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The current work introduces highly dispersed Pt and PtSn catalysts supported on La2O2CO3 nanorods prepared via ultrasonic impregnation, which are used as probe catalysts for the liquid-phase crotonaldehyde hydrogenation. T
- Hou, Fengjun,Zhao, Huahua,Song, Huanling,Chou, Lingjun,Zhao, Jun,Yang, Jian,Yan, Liang
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p. 48649 - 48661
(2017/11/06)
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- Production of conjugated diene compound
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Provided is a method for producing a conjugated diene, in which a gaseous mixture containing an α,β-unsaturated aldehyde and an alcohol in an amount equal to or greater than that of the α,β-unsaturated aldehyde undergoes a hydrogen transfer reaction and a dehydration reaction in the presence of a catalyst obtained by supporting, on a solid oxide carrier, one or more metals selected from the group (I) consisting of Cr, Mn, and Fe, and oxides thereof, and, optionally, one or more metals selected from the group (II) consisting of Co and Ni, and oxides thereof, thereby producing a conjugated diene corresponding to the α, β-unsaturated aldehyde at a high conversion rate and high selectivity.
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Paragraph 0036; 0042
(2017/06/02)
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- Highly selective transfer hydrogenation of α,β-unsaturated carbonyl compounds using Cu-based nanocatalysts
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Simultaneous dehydrogenation of cyclohexanol to cyclohexanone and hydrogenation of α,β-unsaturated carbonyl compounds to corresponding α,β-unsaturated alcohols was carried out in a single pot reaction without addition of any external hydrogen donor. Cu nanoclusters supported on nanocrystalline MgO were found to be the active catalyst for the chemoselective transfer hydrogenation of unsaturated carbonyl compounds to produce the corresponding alcohols with very high yields. Transfer hydrogenation of cyclohexanol and cinnamaldehyde produced cyclohexanone and cinnamyl alcohol with 100% selectivity. This Cu/MgO catalyst can be easily recovered and recycled up to more than five times without any significant loss of activity, which confirmed the true heterogeneous nature of this catalyst. Several α,β-unsaturated compounds were also tested for this reaction and it was found that for all the cases the yield is >95%. The ease of handling without requiring high pressure H2 or a hazardous hydrogen source makes this transfer hydrogenation more practical and useful.
- Siddqui, Nazia,Sarkar, Bipul,Pendem, Chandrashekar,Khatun, Rubina,Sivakumar Konthala,Sasaki, Takehiko,Bordoloi, Ankur,Bal, Rajaram
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p. 2828 - 2837
(2017/07/15)
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- Guerbet Reaction over Strontium-Substituted Hydroxyapatite Catalysts Prepared at Various (Ca+Sr)/P Ratios
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The Guerbet reaction of ethanol to heavier products was performed over a series of extensively characterized Sr-substituted hydroxyapatites (HAPs) with different (Ca+Sr)/P ratios, and thus different structural, textural, and acid–base properties. The acid–base properties were correlated with the reactivity of the solids and an optimal ratio between the amount of acid and basic sites was determined (ca. 4), whereas the ethanol conversion was mainly depending on the specific surface area of the solids. The stoichiometric 100 mol % Sr-substituted sample (SrAp-100) was especially efficient in higher alcohols production, which can be illustrated by a total alcohol selectivity (76.4 %) higher than that of all the other solids at a 13 % ethanol isoconversion.
- Silvester, Lishil,Lamonier, Jean-Fran?ois,Lamonier, Carole,Capron, Micka?l,Vannier, Rose-No?lle,Mamede, Anne-Sophie,Dumeignil, Franck
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p. 2250 - 2261
(2017/06/27)
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- MANUFACTURING METHOD OF UNSATURATED ALCOHOL AND CATALYST
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PROBLEM TO BE SOLVED: To provide a method for selectively manufacturing allyl type unsaturated alcohol form a 1,3-diol type raw material. SOLUTION: There is provided a manufacturing method of aimed allyl type unsaturated alcohol by making zirconia having total percentage content of a fluorite type tetragonal crystal and a fluorite type cubic crystal in an X-ray diffraction to diol represented by the formula (1) of 70% or more, containing at least one kind of dopant selected from alkali earth elements and rare earth elements and total content of the dopant atom to 1 mol of zirconium atom of 0.01 to 0.5 mol act and selectively proceeding one molecule dehydration. In the formula, R1 to R4 are each independently H, a C1 to 5 alkyl group or a C6 to 12 aryl group. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPO&INPIT
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Paragraph 0062; 0063
(2017/05/10)
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- MANUFACTURING METHOD OF DIENE COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for manufacturing a corresponding diene compound from 1,3-diol type raw material, loss in generation of by-product (impurities) impossible to reuse as a raw material. SOLUTION: There is provided a method for manufacturing a diene compound represented by the formula (3) by a first dehydration process for manufacturing unsaturated alcohol from a diol compound with dopant-containing zirconia containing one or more kind of dopant selected from an alkali earth element and a rear earth element with 0.010 to 0.500 mol of total dopant to 1 mol of zirconium atom as a catalyst and a second dehydrating process to manufacture the diene compound from unsaturated alcohol in presence of a dehydration catalyst consisting of one or more kind of compound selected from metal inorganic salt, metal oxide or inorganic acid. (3), R1 to R6 are each independently a C1 to 5 alkyl group or a C6 to 12 aryl group. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0086; 0087
(2018/04/10)
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- PROCESS FOR PRODUCING DIENE COMPOUND
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PROBLEM TO BE SOLVED: To provide a process for efficiently producing a corresponding diene compound from a 1,3-diol type raw material in which the formation of a byproduct that is impossible to be reused as a raw material, is small. SOLUTION: Provided is a process for producing diene compound in which a first dehydration step of producing an unsaturated alcohol from a diol compound represented by formula (1) by using a composite metal oxide having defect fluorite type crystalline structure or pyrochlore type crystalline structure, and a second dehydration step of carrying out dehydration reaction of the unsaturated alcohol in the presence of a dehydration catalyst comprising at least one selected from a metal phosphate, a metal condensed phosphate, a metal hydrochloride, an oxide of a typical metal or an inorganic acid to produce a diene compound, are implemented. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0088-0090
(2018/06/30)
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- Vapor-phase catalytic dehydration of 1,4-butanediol to 3-buten-1-ol over modified ZrO2 catalysts
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Vapor-phase catalytic dehydration of 1,4-butanediol (1,4-BDO) was investigated over modified ZrO2catalysts. In the dehydration of 1,4-BDO over monoclinic ZrO2(m-ZrO2), an unsaturated alcohol, 3-buten-1-ol (3B1OL), was produced together with tetrahydrofuranand γ-butyrolactone. Among alkaline earth metal oxide modifiers, CaO with an appropriate content significantly enhanced the 3B1OL selectivity of m-ZrO2. The modification of CaO was more efficient over m-ZrO2than tetragonal ZrO2. CO2-TPD measurements reveal that CaO supported on m-ZrO2calcined at 800?°C or higher generated new basic sites, which are attributed from Ca-O-Zr hetero-linkages, for the effective formation of 3B1OL from 1,4-BDO. In order to create more Ca-O-Zr hetero-linkages on the m-ZrO2surface efficiently, additional ZrO2was loaded on m-ZrO2together with CaO via a co-impregnation method. At an appropriate weight ratio of CaO/ZrO2?=?7/2 loaded on m-ZrO2, both the 1,4-BDO conversion and the 3B1OL selectivity were enhanced greatly. Especially, the 3B1OL selectivity exceeded 90% at 350?°C.
- Duan, Hailing,Hirota, Tomoya,Ohtsuka, Shota,Yamada, Yasuhiro,Sato, Satoshi
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- Environmentally benign selective hydrogenation of α,β-unsaturated aldehydes and reduction of aromatic nitro compounds using Cu based bimetallic nanoparticles supported on multiwalled carbon nanotubes and mesoporous carbon
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Bimetallic catalysts of Cu with Fe, Co, Ni, Zn or Ru supported on multiwalled carbon nanotubes (MWCNT) and mesoporous carbon (MC) were prepared by in situ reduction of CuCl2 and the metal chlorides using NaBH4. The catalytic activity of these materials was investigated in the hydrogenation of α,β-unsaturated aldehydes and reduction of aromatic nitro compounds using different hydrogen sources. Cu-Ni and Cu-Ru supported on MWCNT catalysts were found to be better than MC supported catalysts in terms of yield of the expected product and recyclability. Among the different hydrogen sources used, molecular H2 was found to be the best for the hydrogenation of α,β-unsaturated aldehydes to corresponding alcohols (conversion 83-86%, selectivity 72-78%), whereas NaBH4 was the best for the reduction of aromatic nitro compounds to corresponding amines (conversion 100%, selectivity 98%). The reaction conditions were optimised for good yield and selectivity of the product. Generality of the catalysts was also investigated in the reduction of different α,β-unsaturated aldehydes and aromatic nitro compounds. The relationship between catalytic activity and physico-chemical properties was investigated by characterising the catalytic materials using powder X-ray diffraction (powder XRD), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface area, scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM).
- Hareesh,Minchitha,Venkatesh,Nagaraju,Kathyayini
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p. 82359 - 82369
(2016/09/09)
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- Chemoselective Hydrogenation of Crotonaldehyde Catalyzed by an Au@ZIF-8 Composite
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Au nanoparticles of size 2.2 nm were encapsulated in a zeolitic imidazolate framework ZIF-8 framework (Au@ZIF-8). The composite was used as a catalyst for the selective hydrogenation of crotonaldehyde to crotyl alcohol with 90-95 % selectivity. Hydrogenation of 1-hexene yielded n-hexane in approximately the same conversion as crotonaldehyde, whereas cis-cyclohexene did not detectably react. To account for the confined environment of the ZIF, we supported Au nanoparticles on the outside of ZIF-8 (Au/ZIF-8). Using Au/ZIF-8 as a catalyst, 1-hexene and cis-cyclohexene were hydrogenated in low conversion whereas crotonaldehyde would only react at higher pressures in 70 % selectivity towards crotyl alcohol. Post-experiment TEM analysis of Au/ZIF-8 showed significant sintering whereas the median particle size of Au@ZIF-8 remained almost unchanged. Au@ZIF-8 was recycled as a catalyst for the hydrogenation of crotonaldehyde three times without significant loss of activity or selectivity.
- Stephenson, Casey J.,Whitford, Cassandra L.,Stair, Peter C.,Farha, Omar K.,Hupp, Joseph T.
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p. 855 - 860
(2016/03/05)
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- Carboxylic group embedded carbon balls as a new supported catalyst for hydrogen economic reactions
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Carboxylic group functionalized carbon balls have been successfully synthesized by using a facile synthesis method and well characterized with different characterization techniques such as XPS, MAS NMR, SEM, ICP and N2 physi-sorption analysis. The synthesized material has been effectively utilized as novel support to immobilized ruthenium catalyst for hydrogen economic reactions.
- Bordoloi, Ankur
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p. 3071 - 3076
(2016/03/19)
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- MICROORGANISMS FOR PRODUCING 4C-5C COMPOUNDS WITH UNSATURATION AND METHODS RELATED THERETO
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The invention provides a non-naturally occurring microbial organism having a butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol, pathway. The microbial organism contains at least one exogenous nucleic acid encoding an enzyme in a pathway. The invention additionally provides a method for producing butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol,. The method can include culturing a butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol-producing microbial organism, where the microbial organism expresses at least one exogenous nucleic acid encoding a pathway enzyme in a sufficient amount, and under conditions and for a sufficient period of time to produce butadiene, crotyl alcohol, 2,4-pentadienoate, 3-buten-2-ol, or 3-buten-1-ol.
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Paragraph 0014; 00100
(2016/01/25)
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- Enhancing Metal-Support Interactions by Molybdenum Carbide: An Efficient Strategy toward the Chemoselective Hydrogenation of α,β-Unsaturated Aldehydes
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Metal-support interactions are desired to optimize the catalytic turnover on metals. Herein, the enhanced interactions by using a Mo2C nanowires support were utilized to modify the charge density of an Ir surface, accomplishing the selective hydrogenation of α,β-unsaturated aldehydes on negatively charged Irδ- species. The combined experimental and theoretical investigations showed that the Irδ- species derive from the higher work function of Ir (vs. Mo2C) and the consequently electron transfer. In crotonaldehyde hydrogenation, Ir/Mo2C delivered a crotyl alcohol selectivity as high as 80 %, outperforming those of counterparts (2C was highlighted by its higher selectivity as well as the better activity. Additionally, the efficacy for various substrates further verified our Ir/Mo2C system to be competitive for chemoselective hydrogenation.
- He, Sina,Shao, Zheng-Jiang,Shu, Yijin,Shi, Zhangping,Cao, Xiao-Ming,Gao, Qingsheng,Hu, Peijun,Tang, Yi
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supporting information
p. 5698 - 5704
(2016/04/20)
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- Manganese(III) porphyrin anchored onto multiwall carbon nanotubes: An efficient and reusable catalyst for the heterogeneous reduction of aldehydes and ketones
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Reduction of a variety of carbonyl compounds with NaBH4, using Mn-porphyrin, meso-tetrakis(4-hydroxyphenyl)porphyrinatomanganese(III), supported onto functionalized multiwall carbon nanotubes has been investigated. The heterogeneous catalyst was characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis spectroscopy. The amount of catalyst loading on the nanotubes was determined by atomic absorption spectroscopy. Thermogravimetric analysis (TGA) demonstrated that the nanocatalyst was thermally stable to almost 300 °C, exhibiting high thermostability of the catalyst over a broad range of temperatures. This heterogeneous catalyst proved to be an efficient catalyst in the aerobic reduction of various aldehydes and ketones with NaBH4. In the presence of the nanocatalyst, NaBH4 can readily reduce a variety of aldehydes in good to excellent yields (50-100%) and ketones in excellent yields (100%) to their corresponding alcohols. The separation of the catalyst is very simple and economic. Also, FTIR spectra after four successive cycles showed that the catalyst was strongly anchored to the nanotubes.
- Rayati, Saeed,Bohloulbandi, Elaheh,Zakavi, Saeed
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p. 638 - 649
(2016/03/12)
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