- Stelliosphaerols A and B, Sesquiterpene-Polyol Conjugates from an Ecuadorian Fungal Endophyte
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Endophytic fungi are plant tissue-associated fungi that represent a rich resource of unexplored biological and chemical diversity. As part of an ongoing effort to characterize Amazon rainforest-derived endophytes, numerous fungi were isolated and cultured from plants collected in the Yasun National Park in Ecuador. Of these samples, phylogenetic and morphological data revealed a previously undescribed fungus in the order Pleosporales that was cultured from the tropical tree Duroia hirsuta. Extracts from this fungal isolate displayed activity against Staphylococcus aureus and were thus subjected to detailed chemical studies. Two compounds with modest antibacterial activity were isolated, and their structures were elucidated using a combination of NMR spectroscopic analysis, LC-MS studies, and chemical degradation. These efforts led to the identification of stelliosphaerols A (1) and B (2), new sesquiterpene-polyol conjugates that are responsible, at least in part, for the S. aureus inhibitory activity of the fungal extract.
- Forcina, Giovanni C.,Castro, Amaya,Bokesch, Heidi R.,Spakowicz, Daniel J.,Legaspi, Michelle E.,Kucera, Kaury,Villota, Stephany,Narvez-Trujillo, Alexandra,McMahon, James B.,Gustafson, Kirk R.,Strobel, Scott A.
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- Rapid, one pot preparation of D-mannose and D-mannitol from starch: The effect of microwave irradiation and MoVI catalyst
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The effect of microwave irradiation upon starch hydrolysis and simultaneous epimerization of the D-glucose to D-mannose obtained was investigated. An acidic aqueous solution of starch was treated with a catalytic amount of hexavalent molybdenum salt in microwave field and the composition of the reaction mixture was analyzed. Rapid starch hydrolysis and subsequent epimerization provided an equilibrium reaction mixture of D-glucose and D-mannose (2:1) without the formation of any undesirable by-products. The reduction of D-mannose with sodium borohydride yielded D-mannitol in very good yield. Microwave irradiation proved to be an efficient tool for the transformation of starch to mannose over an MoVI catalyst. This method has the advantages of environmental friendliness, easy operation, good yields and substantial reduction of reaction time.
- Hricoviniova, Zuzana
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- Seven new drimane-type sesquiterpenoids from a marine-derived fungus paraconiothyrium sporulosum YK-03
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Seven new drimane-type sesquiterpenoids, namely the sporulositols A-D (1-4), 6-hydroxydiaporol (5), seco-sporulositol (6) and sporuloside (7) were isolated from the ethyl acetate extract of fermentation broth for a marine-derived fungus Paraconiothyrium sporulosum YK-03. Their structureswere elucidated by analysis of extensive spectroscopic data, and the absolute configurations were established by crystal X-ray diffraction analysis and comparisons of circular dichroism data. Among them, sporulositols A-E (1-4) and seco-sporulositol (6) represent the first five examples of a unique class of drimanic mannitol derivatives, while compounds 6 and 7 may represent two new series of natural drimanes, possessing an aromatic ring with a rare 4,5-secodrimanic skeleton and an unusual CH3-15 rearranged drimanic α-D-glucopyranside, respectively. Furthermore, the origin of mannitol moiety was investigated by reliable HPLC and NMR analyses.
- Zhang, Li-Hua,Chen, Gang,Sun, Yi,Wang, Hai-Feng,Bai, Jiao,Hua, Hui-Ming,Pei, Yue-Hu
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- Iridoid and phenylethanoid glucosides from veronica lavaudiana
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From an extract of Veronica (sect. Hebe) lavaudiana we have identified mannitol and isolated 11 iridoid glucosides, the carbohydrate ester hebitol II, and four phenylethanoid glycoside esters. Five of the iridoid glycosides are new; of these, lavaudiosides A, B, and C (2a, 3a, and 4) are 1-mannityl esters of 8-epiloganic acid, while 7e and 7f are 6′-O-caffeoyl derivatives of catalpol. The new phenylethanoid glycoside esters, heliosides A, B, and C (8b - d), are 6′-xylosyl derivatives of aragoside. The structures of the new compounds were elucidated mainly by spectroscopic analysis, but also by chemical degradation. We also demonstrated that the structures of the known glycosides globularitol and hebitols I and II should be revised. These compounds are derivatives of mannitol and not glucitol as previously believed.
- Taskova, Rilka M.,Kokubun, Tetsuo,Ryan, Ken G.,Garnock-Jones, Phil J.,Jensen, Soren R.
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- Selective hydrogenation of d-mannose to d-mannitol using NiO-modified TiO2 (NiO-TiO2) supported ruthenium catalyst
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NiO-modified TiO2 (NiO-TiO2) supported ruthenium catalyst Ru/(NiO-TiO2) is prepared by simple impregnation method and characterized by using energy dispersive X-ray analysis (EDX/EDS), temperature- programmed reduction (TPR), inductively coupled plasma (ICP) mass spectrometry, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and CO chemisorption. The catalyst Ru/(NiO-TiO2) is evaluated in d-mannose hydrogenation and hydrogenation experiments to produce a selective product d-mannitol were carried out batch wise in a three-phase laboratory scale reactor. A tentative mechanism for reduction of d-mannose is presented. The kinetics of d-mannose hydrogenation to d-mannitol using catalyst Ru/(NiO-TiO2) was studied. The kinetic data were modeled by zero, first and second-order reaction equations. A set of four experiments was also carried out to test the deactivation of the catalyst. For affording maximum d-mannose conversion, yield and selectivity to d-mannitol, the reaction conditions are optimized.
- Mishra, Dinesh Kumar,Hwang, Jin-Soo
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- Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses
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Sugar alcohols are of great importance for the food industry and are promising building blocks for bio-based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on commercially available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi-gram scale allowing sugar alcohols to be isolated in large quantities at high atom economy.
- Tindall, Daniel J.,Mader, Steffen,Kindler, Alois,Rominger, Frank,Hashmi, A. Stephen K.,Schaub, Thomas
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supporting information
p. 721 - 725
(2020/10/19)
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- Product Control and Insight into Conversion of C6 Aldose Toward C2, C4 and C6 Alditols in One-Pot Retro-Aldol Condensation and Hydrogenation Processes
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Alcohols have a wide range of applicability, and their functions vary with the carbon numbers. C6 and C4 alditols are alternative of sweetener, as well as significant pharmaceutical and chemical intermediates, which are mainly obtained through the fermentation of microorganism currently. Similarly, as a bulk chemical, C2 alditol plays a decisive role in chemical synthesis. However, among them, few works have been focused on the chemical production of C4 alditol yet due to its difficult accumulation. In this paper, under a static and semi-flowing procedure, we have achieved the product control during the conversion of C6 aldose toward C6 alditol, C4 alditol and C2 alditol, respectively. About C4 alditol yield of 20 % and C4 plus C6 alditols yield of 60 % are acquired in the one-pot conversion via a cascade retro-aldol condensation and hydrogenation process. Furthermore, in the semi-flowing condition, the yield of ethylene glycol is up to 73 % thanks to its low instantaneous concentration.
- Gao, Lou,Hou, Wenrong,Hui, Yingshuang,Tang, Yi,Zhan, Yulu,Zhang, Yahong
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p. 560 - 566
(2021/06/25)
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- Efficient Synthesis of Sugar Alcohols over a Synergistic and Sustainable Catalyst
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A series of catalysts were prepared for sugar alcohols production to overcome the deficiencies of the previous reported catalysts, such as low yield of sugar alcohols, single function, instability, and controversial role of active sites. The role of each metal and their synergistic-cooperation was discussed in detail with a combination of conditional experiments and characterizations. The results indicated that bifunctional Ni6.66Fe1Al1.55 catalyst has unique structure with superparamagnetism and excellent activity. The (111) and (200) planes of metallic Ni are the hydrogenation active phases and preferentially exposed on Ni-Al-Ox spinel. The desired arabitol or mannitol was obtained by tuning the ratio of Br?nsted and Lewis acid sites. The recycling tests indicated that the unique structure of the prepared Ni-based catalyst can suppress leaching and poisoning, which has high textural stability and activity.
- Lin, Lu,Qiu, Jiarong,Sun, Yong,Tang, Xing,Zeng, Xianhai,Zhang, Liangqing
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p. 2467 - 2476
(2021/07/16)
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- Elucidating the effect of solid base on the hydrogenation of C5 and C6 sugars over Pt–Sn bimetallic catalyst at room temperature
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Conversion of sugars into sugar alcohols at room temperature with exceedingly high yields are achieved over Pt–Sn/γ-Al2O3 catalyst in the presence of calcined hydrotalcite. pH of the reaction mixture significantly affects the conversion and selectivity for sugar alcohols. Selection of a suitable base is the key to achieve optimum yields. Various solid bases in combination with Pt–Sn/γ-Al2O3 catalysts were evaluated for hydrogenation of sugars. Amongst all combinations, the mixture (1:1 wt/wt) of Pt–Sn/γ-Al2O3 and calcined hydrotalcite showed the best results. Hydrotalcite helps to make the pH of reaction mixture alkaline at which sugar molecules undergo ring opening. The sugar molecule in open chain form has carbonyl group which can be polarized by Sn in Pt–Sn/γ-Al2O3 and Pt facilitates the hydrogenation. In the current work, effect of both; solid base and Sn as a promoter has been studied to improve the yields of sugar alcohols from various C5 and C6 sugars at very mild reaction conditions.
- Tathod, Anup P.,Dhepe, Paresh L.
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- Glycosides from Buddleja officinalis with their protective effects on photoreceptor cells in light-damaged mouse retinas
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A new phenylethanoid, hebitol IV (1), along with fifteen known glycosides (2-16), were isolated from water extract of the flower buds of Buddleja officinalis. Their structures were elucidated on the basis of 1 D-NMR, 2 D-NMR and MS data. Molecular docking showed the potential activities of the natural products against VEGFR-2. Bioassay results revealed that the compounds 10 and 14 exhibited strong inhibitory activity against VEGFR-2 with IC50 values of 0.51 and 0.32 μM, respectively. Moreover, the potential retinal protective effects of 10 and 14 were then investigated in the mouse model featuring bright light-induced retinal degeneration. The results demonstrated remarkable photoreceptor protective activities of 10 and 14in?vivo.
- Chen, Yu,Du, Xiaoye,Jia, Qi,Li, Bo,Li, Yiming,Long, Zehai,Wang, Qiyao,Xu, Zhijian,Zhang, Yong,Zhu, Weiliang
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- A Robust and Highly Selective Catalytic System of Copper–Silica Nanocomposite and 1-Butanol in Fructose Hydrogenation to Mannitol
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We report for the first time the selective production of mannitol, a low-calorie sweetener and an important pharmaceutical ingredient, from fructose using Cu?SiO2 nanocomposite as catalyst and 1-butanol as solvent. When compared with water and ethanol, a lower fructose solubility was achieved in 1-butanol, which caused a lower fructose conversion and higher mannitol selectivity by reducing formation of side products. Among various Cu-based catalysts in 1-butanol, Cu(80)?SiO2 nanocomposite gave an unprecedented mannitol (83 %) and sorbitol (15 %) yield at 120 °C, 35 bar H2, and 10 h reaction time. More importantly, this catalyst did not show any Cu leaching and its physicochemical properties were maintained after liquid-phase fructose hydrogenation whereas other Cu-based catalysts such as Cu(32)?Cr2O and Cu(66)?ZnO did show significant leaching of Cu and Cr. Thus, Cu(80)?SiO2 nanocomposite and 1-butanol are regarded as a robust and highly efficient catalytic system for the selective hydrogenation of fructose to mannitol. Also, density functional theory calculations supported that in addition to the stable initial structure of adsorbed fructose, the mannitol pathway was more thermodynamically favorable than the sorbitol pathway. Notably, the highly pure mannitol (99 %) could be recovered from the sorbitol-containing 1-butanol solution by simple filtration. Therefore, the present protocol is a novel and effective method to produce pure mannitol from fructose in both an environmental and an industrial context.
- Upare, Pravin P.,Hwang, Young Kyu,Kim, Jin Chul,Lee, Jeong Hyeon,Kwak, Sang Kyu,Hwang, Dong Won
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p. 5050 - 5057
(2020/08/05)
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- The effect of physical morphology and the chemical state of Ru on the catalytic properties of Ru-carbon for cellulose hydrolytic hydrogenation
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Ru-carbon catalysts with different physical morphologies and chemical states of Ru were prepared by different methods and used to catalyze the hydrolytic hydrogenation of cellulose at high temperatures. The physical morphology of Ru particles and the chemical state of Ru significantly influenced the catalytic performance. The Ru nanoparticles in Ru@MC prepared by thein situcarbothermal reduction method exhibited a special chemical state due to the strong interaction with carbon. The special structure could not only prevent the growth of Ru particles but also enhance the hydrogen spillover effect and improve the hydrogenation efficiency. Among the Ru-carbon catalysts, Ru@MC showed the best catalytic performance with a 72.4% yield of sorbitol. Furthermore, the embedded structure of Ru@MC stabilized the Ru nanoparticles, and the catalyst could be reused at least 6 times.
- Zhang, Gang,Chen, Tong,Zhang, Yi,Liu, Tao,Wang, Gongying
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p. 15169 - 15176
(2020/10/02)
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- Hydrogenation of crude and purified d-glucosone generated by enzymatic oxidation of d-glucose
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D-Fructose is an important starting material for producing furfurals and other industrially important chemicals. While the base-catalyzed and enzymatic conversion of d-glucose to d-fructose is well known, the employed methods typically provide limited conversion. d-Glucosone can be obtained from d-glucose by enzymatic oxidation at the C2 position and, subsequently, selectively hydrogenated at C1 to form d-fructose. This work describes an investigation on the hydrogenation of d-glucosone, using both chromatographically purified and crude material obtained directly from the enzymatic oxidation, subjected to filtration and lyophilization only. High selectivities towards d-fructose were observed for both starting materials over a Ru/C catalyst. Hydrogenation of the crude d-glucosone was, however, inhibited by the impurities resulting from the enzymatic oxidation process. Catalyst deactivation was observed in the case of both starting materials.
- Aho, Atte,Lassfolk, Robert,Leino, Reko,Murzin, Dmitry Yu.
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p. 30476 - 30480
(2020/09/11)
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- Direct conversion of cellulose into isosorbide over Ni doped NbOPO4catalysts in water
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Isosorbide is a versatile chemical intermediate for the production of a variety of drugs, chemicals, and polymers, and its efficient production from natural cellulose is of great significance. In this study, bifunctional catalysts based on niobium phosphates were prepared by a facile hydrothermal method and used for the direct conversion of cellulose to isosorbide under aqueous conditions. NH3-TPD analysis showed that a high acid content existed on the catalyst surface, and pyridine infrared spectroscopic analysis confirmed the presence of both Lewis acid and Br?nsted acid sites, both of which played an important role in the process of carbohydrate conversion. XRD and H2-TPR characterization determined the composition and the hydrogenation centers of the catalyst. An isosorbide yield of 47% could be obtained at 200 °C for 24 h under 3 MPa H2 pressure. The Ni/NbOPO4 bifunctional catalyst retains most of its activity after five consecutive runs with slightly decreased isosorbide yield of 44%. In addition, a possible reaction mechanism was proposed that the synergistic effect of surface acid sites and hydrogenation sites was favorable to enhancing the cascade dehydration and hydrogenation reactions during the conversion of cellulose to isosorbide. This study provides as an efficient strategy for the development of novel multifunctional heterogeneous catalysts for the one-pot valorisation of cellulose. This journal is
- Guo, Jiaxing,He, Minyao,Li, Cuiqing,Liu, ShanShan,Song, Yongji,Wang, Hong,Wang, Xincheng
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supporting information
p. 10292 - 10299
(2020/07/14)
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- Harnessing the reactivity of poly(methylhydrosiloxane) for the reduction and cyclization of biomass to high-value products
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Poly(methylhydrosiloxane) (PMHS) has been examined for its ability to reduce and subsequently cyclize carbohydrate substrates using catalytic tris(pentafluorophenyl)borane (BCF). The work herein is the first reported example of the direct conversion of monosaccharides to 1,4-anhydro and 2,5-anhydro products utilizing a hydrosiloxane reducing agent. PMHS is produced from waste products of the silicone industry, making it a green alternative to traditional hydrosilane reducing agents. This work thus contributes to the goal of utilizing renewable feedstocks in the production of fine-chemicals.
- Hein, Nicholas M.,Seo, Youngran,Lee, Stephen J.,Gagné, Michel R.
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p. 2662 - 2669
(2019/06/13)
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- Effect of carbon chain length on catalytic C–O bond cleavage of polyols over Rh-ReOx/ZrO2 in aqueous phase
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Production of linear deoxygenated C4 (butanetriols, -diols, and butanols), C5 (pentanetetraols, -triols, -diols, and pentanols), and C6 products (hexanepentaols, -tetraols, -triols, -diols, and hexanols) is achievable by hydrogenolysis of erythritol, xylitol, and sorbitol over supported-bimetallic Rh-ReOx (Re/Rh molar ratio 0.5) catalyst, respectively. After validation of the analytical methodology, the effect of some reaction parameters was studied. In addition to C–O bond cleavage by hydrogenolysis, these polyols can undergo parallel reactions such as epimerization, cyclic dehydration, and C–C bond cleavage. The time courses of each family of linear deoxygenated C4, C5, and C6 products confirmed that the sequence of appearance of the different categories of deoxygenated products followed a multiple sequential deoxygenation pathway. The highest selectivity to a mixture of linear deoxygenated C4, C5, and C6 products at 80percent conversion was favoured under high pressure in the presence of 3.7wt.percentRh-3.5wt.percentReOx/ZrO2 catalysts (54–71percent under 80 bar) at 200 °C.
- Besson, Michèle,Da Silva Perez, Denilson,Perret, Noémie,Pinel, Catherine,Sadier, Achraf
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- Effect of Cu addition to carbon-supported Ru catalysts on hydrogenation of alginic acid into sugar alcohols
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The objective of this study was to investigate the effect of Cu addition to carbon supported Ru catalysts on the hydrogenation of macroalgae-derived alginic acid into sugar alcohols, mainly sorbitol and mannitol. Both geometric and electronic effects were determined based on results of H2-TPR, H2- or CO-chemisorption, and XPS analyses after Cu was added to Ru. The addition of Cu to Ru caused blocking of active Ru surface and electron transfer between Ru and Cu. The intimate interaction between Ru and Cu formed RuCu bimetallic clusters which expedited hydrogen spillover from Ru to Cu. The highest yield of target sugar alcohols of 47.4% was obtained when 5 wt% of Ru and 1 wt% of Cu supported on nitric acid-treated activated carbon reacted at 180 °C for 2 h. The RuCu bimetallic catalyst exhibited deactivation upon repeated reactions due to the carbon deposition on the catalyst.
- Ban, Chunghyeon,Yang, Seungdo,Kim, Hyungjoo,Kim, Do Heui
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- Synergistic effect between copper and different metal oxides in the selective hydrogenolysis of glucose
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Copper catalysts have been extensively applied in saccharide hydrogenolysis for their high selectivity to C-O bond cleavage. The hydrogenolysis of glucose contains many reaction procedures, which need the synergistic effect of different active sites. A series of Cu catalysts supported on metal oxides with different surface physicochemical properties were prepared. The metal oxide supports not only influence the properties of Cu, such as dispersion and the electronic state, but also affect the activity of C-C and C-O bond cleavage in glucose. Furthermore, the coordination of a large amount of Lewis acid sites and hydrogenation sites on a Cu/γ-Al2O3 catalyst can promote C-C and C-O bond cleavage, leading to the selective conversion of glucose to glycol (selectivity of 66.6%). A Cu/MgO catalyst with a large amount of basic sites and metal sites could accelerate the retro-aldol condensation and isomerization reactions simultaneously, resulting in the main products of C2, C3, and C4 polyols. A study of the synergistic effect between other transition metals and γ-Al2O3 showed that Pd had high activity for central C-C bond cleavage in glucose. Ru provided extremely strong activity for C-C bond cleavage at the terminal of the carbon chain in glucose, with the main product being methane (selectivity of 66.4%).
- Liu, Chengwei,Zhang, Zhaonan,Zhai, Xuefeng,Wang, Xianzhou,Gui, Jianzhou,Zhang, Chenghua,Zhu, Yulei,Li, Yongwang
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p. 3733 - 3742
(2019/03/05)
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- Highly efficient catalytic conversion of cellulose into acetol over Ni-Sn supported on nanosilica and the mechanism study
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Selective conversion of cellulose into high value-added C3 chemicals is a great challenge in biorefinery due to the complicated reaction process. In this work, 61.6% yield of acetol was obtained by one pot conversion of cellulose using Ni-Sn/SiO2 catalysts. A series of characterization methods including TEM, STEM-HAADF, EDS, AAS, XRD, XPS, H2-TPR, Py-FTIR, and CO2-TPD were carried out to explore the structure-activity relationship. The strong basicity of the catalysts was a key factor affecting the production of acetol. In addition, catalysts with the hydrothermally stable L-acid sites and no B-acid sites inhibited side reactions and ensured efficient conversion of cellulose into small molecules. Further studies showed that the formation of the Ni3Sn4 alloy significantly promoted the acetol production, and its weak hydrogenation activity inhibited further conversion of acetol. Noninteger valence tin species (Snδ+ and SnOx) were formed both in Ni3Sn4 and Sn/SiO2. These Sn species were the source of basic sites and the active sites for catalyzing cellulose to acetol. Under the synergistic catalysis of Sn/SiO2 and the Ni3Sn4 alloy, cellulose was efficiently converted into acetol. This work provides guidance for the selective conversion of cellulose into C3 products.
- Liu, Xiaohao,Liu, Xiaodong,Xu, Guangyue,Zhang, Ying,Wang, Chenguang,Lu, Qiang,Ma, Longlong
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p. 5647 - 5656
(2019/11/05)
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- Method for preparation of mannitol from fructose using butanol as solvent
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The present invention relates to a method for preparing mannitol which includes performing the hydrogenation of fructose in the presence of a Cu-based nanocomposite catalyst, for example, a nanocomposite catalyst of CuO(x)/SiO2(100-x) (wherein x is a real number from 20 to 90), using butanol as a solvent.
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Page/Page column 6; 8; 9
(2018/12/11)
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- Method for preparation of mannitol from fructose using butanol as solvent
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The present invention relates to a production method of mannitol including a step of performing hydrogenation of fructose using butanol as a solvent and using a Cu-based nanocomposite catalyst, for example, a CuO(x)/SiO_2(100-x) catalyst (x is a real number from 20 to 90). Mannitol can be produced with high yield and selectivity through the production method of the present invention.COPYRIGHT KIPO 2018
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Paragraph 0060; 0062; 0100; 0102; 0120; 0122; 0123
(2019/01/09)
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- Method for preparing sugar alcohol and coproducing white carbon black
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The invention relates to a method for preparing sugar alcohol and coproducing white carbon black. The method comprises the following steps: mixing raw sugar and a water-soluble strong alkali solution;adding silicon and a catalyst; removing oxygen and stirring and reacting at 100 to 200 DEG C under a sealed state; filtering to obtain filtrate C and filtering residue D; adding acid into the filtrate C and regulating the pH (Potential of Hydrogen); stirring and reacting, and filtering to obtain filtrate E and a solid F; drying the solid F to obtain the white carbon black; carrying out electrodialysis desalination on the filtrate E to obtain a sugar alcohol solution G; concentrating, spraying and drying the sugar alcohol solution G to obtain the sugar alcohol. According to the method providedby the invention, hydrogen gas generated through reaction of silicon and strong alkali is used as a reducing agent, and hydrogen gas does not need to be additionally introduced or other reducing agents do not need to be additionally added; unreacted substances and products can be repeatedly utilized and pollution caused by three wastes is not caused; the purity of the prepared sugar alcohol can reach 90 percent or more and the white carbon black can reach HG/T 3061-2009 A type standards.
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Paragraph 0089-0097
(2018/06/04)
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- Integration of Enzymatic and Heterogeneous Catalysis for One-Pot Production of Fructose from Glucose
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The search for efficient routes for the production of fructose from biomass-derived glucose is of great interest and importance, as fructose is a highly attractive substrate in the conversion of cellulosic biomass into biofuels and chemicals. In this study, a one-pot, multistep procedure involving enzyme-catalyzed oxidation of glucose at C2 and Ni/C-catalyzed hydrogenation of d-glucosone at C1 selectively gives fructose in 77 % yield. Starting from upstream substrates such as α-cellulose and starch, fructose was also generated with similar efficiency and selectivity by the combination of enzymatic and heterogeneous catalysis. This method constitutes a new means of preparing fructose from biomass-derived substrates in an efficient fashion.
- Sun, Jiankui,Li, Helong,Huang, Hongzhi,Wang, Bo,Xiao, Ling-Ping,Song, Guoyong
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p. 1157 - 1162
(2018/03/21)
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- PROCESS FOR THE PRODUCTION OF GLYCOLS
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The invention provides a process for the preparation of glycols from a saccharide-containing feedstock in a reactor system, said process comprising: i) providing a first feed stream comprising said saccharide-containing feedstock in a first solvent at a temperature of no more than 160°C; ii) providing a second feed stream comprising a tungsten- based retro-aldol catalytic species and an alkali metal containing species in a second solvent at a temperature in the range of from 150 to 250°C; iii) combining the first feed stream and the second feed stream, before they are provided to the reactor system, to form a combined feed stream; iv) providing the combined feed stream to the reactor system and operating the reactor at a temperature in the range of from 150°C to 250°C; and v) also contacting the combined feed stream with a hydrogenation catalytic species in the presence of hydrogen, wherein the molar ratio of alkali metal:tungsten in the combined feed stream is in the range of from 0.55 to 6.
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Page/Page column 13-16
(2018/03/28)
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- Production of ethylene glycol from direct catalytic conversion of cellulose over a binary catalyst of metal-loaded modified SBA-15 and phosphotungstic acid
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This study presents the utilization of a binary catalyst composed of metal-loaded modified SBA-15 (M/SBA-15) and phosphotungstic acid (H3PW12O40) for ethylene glycol (EG) production from direct catalytic conversion of cell
- Yu, Shitao,Cao, Xincheng,Liu, Shiwei,Li, Lu,Wu, Qiong
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p. 24857 - 24865
(2018/07/29)
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- Transfer Hydrogenation of Aldehydes and Ketones with Isopropanol under Neutral Conditions Catalyzed by a Metal-Ligand Bifunctional Catalyst [Cp?Ir(2,2′-bpyO)(H2O)]
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A Cp?Ir complex bearing a functional bipyridonate ligand [Cp?Ir(2,2′-bpyO)(H2O)] was found to be a highly efficient and general catalyst for transfer hydrogenation of aldehydes and chemoselective transfer hydrogenation of unsaturated aldehydes with isopropanol under neutral conditions. It was noteworthy that many readily reducible or labile functional groups such as nitro, cyano, ester, and halide did not undergo any change under the reaction conditions. Furthermore, this catalytic system exhibited high activity for transfer hydrogenation of ketones with isopropanol. Notably, this research exhibited new potential of metal-ligand bifunctional catalysts for transfer hydrogenation.
- Wang, Rongzhou,Tang, Yawen,Xu, Meng,Meng, Chong,Li, Feng
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p. 2274 - 2281
(2018/02/23)
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- Hydrothermally Stable Ruthenium–Zirconium–Tungsten Catalyst for Cellulose Hydrogenolysis to Polyols
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In this work, we describe a catalytic material based on a zirconium–tungsten oxide with ruthenium for the hydrogenolysis of microcrystalline cellulose under hydrothermal conditions. With these catalysts, polyols can be produced with high yields. High and stable polyol yields were also achieved in recycling tests. A catalyst with 4.5 wt % ruthenium in total achieved a carbon efficiency of almost 100 %. The prepared Zr-W oxide is mesoporous and largely stable under hydrothermal conditions (493 K and 65 bar hydrogen). Decomposition into the components ZrO2 and WO3 could be observed at temperatures of 1050 K in air.
- Lucas, Martin,Fabi?ovicová, Katarina,Claus, Peter
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p. 612 - 618
(2017/12/28)
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- Role of the Strong Lewis Base Sites on Glucose Hydrogenolysis
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This work reports the individual role of strong Lewis base sites on catalytic conversion of glucose hydrogenolysis to acetol/lactic acid, including glucose isomerisation to fructose and pyruvaldehyde rearrangement/hydrogenation to acetol/lactic acid. Las
- Yazdani, Parviz,Wang, Bo,Gao, Feng,Kawi, Sibudjing,Borgna, Armando
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p. 3845 - 3853
(2018/07/31)
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- Influence of the Surface Chemistry of Multiwalled Carbon Nanotubes on the Selective Conversion of Cellulose into Sorbitol
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Carbon nanotubes (CNT) were submitted to liquid-phase chemical treatments using HNO3 and subsequently to gas-phase thermal treatments to incorporate different sets of oxygenated groups on the surface. The modified CNT were used as supports for 0.4 wt % Ru in the direct conversion of ball-milled cellulose to sorbitol and high conversions were reached after 3 h at 205 °C. Ru supported on the original CNT, although less active, was the most selective catalyst for the one-pot process (70 % sorbitol selectivity after 2 h). Unlike the one-pot process, the support acidity greatly promoted the rate of cellulose hydrolysis (35 % increase after 2 h) and the glucose selectivity (12 % increase after 2 h). The rate of glucose hydrogenation was almost not affected by the support modification. However, the catalyst acidity improved the sorbitol selectivity from glucose. The support acidity was a central factor for the one-pot conversion of cellulose, as well as for the individual hydrolysis and hydrogenation steps, and the original CNT supported Ru catalyst was the most efficient and selective catalyst for the direct conversion of cellulose to sorbitol.
- Ribeiro, Lucília S.,Delgado, Juan J.,de Melo órf?o, José J.,Ribeiro Pereira, M. Fernando
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p. 888 - 896
(2017/03/13)
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- A using a supported metal catalyst method for preparing alcohols (by machine translation)
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The invention provides a method for using a supported metal catalyst for producing alcohol, comprising the following steps: carbonyl-containing compounds in the supported metal catalyst under the catalytic action of, and H2 To carry out the reduction reaction, to obtain the alcohol compound; the supported metal catalyst includes: catalyst carrier, loaded on the catalyst carrier and the metal; the metal for the 8th group metal in one or more of; the catalyst carrier is zirconium oxide, lanthanide metal oxide, lanthanide metal oxide-modified zirconia, 4th cycle transition metal oxide modified zirconia, 5th cycle transition metal oxide modified zirconia, alkaline earth metal oxide modified zirconium oxide or aluminum oxide modified zirconia. This invention adopts the above-mentioned particular catalyst for producing alcohol, has high conversion rate, good selectivity, mild reaction conditions, simple device and the like, it has good industrial application prospect. (by machine translation)
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Paragraph 0056-0061
(2017/09/01)
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- NOVEL LACTIC ACID BACTERIUM
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This invention provides lactic acid bacteria that have one or more effects selected from among fatigue-ameliorating effect, blood circulation-improving effect, stool odor-reducing effect, and growth-promoting effect and that can be used with high safety. This invention further provides a pharmaceutical preparation comprising, as an active ingredient, lactic acid bacteria that have one or more effects selected from among fatigue-ameliorating effect, blood circulation-improving effect, stool odor-reducing effect, and growth-promoting effect. According to the invention, novel lactic acid bacteria belonging to the Enterococcus faecium species having particular mycological properties and exhibiting viability of 40% or higher when freeze-dried in the absence of a dispersion medium and viability of 80% or higher in a probiotic preparation when stored at 40° C. for 4 months, a composition comprising such lactic acid bacteria, an agent for ameliorating fatigue, improving blood circulation, reducing stool odor or promoting growth comprising, as an active ingredient, such composition, and use of such composition for food and other products.
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- Bimetallic Ru:Ni/MCM-48 catalysts for the effective hydrogenation of D-glucose into sorbitol
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Three different bimetallic Ru:Ni catalysts supported on a mesoporous silica MCM-48 were prepared by consecutive wet impregnations, with a total metal loading of ca. 3% (w w?1). Ru:Ni ratios spanned in the range of 0.15–1.39 (w w?1) and were compared with the corresponding monometallic Ni/MCM-48. The catalysts so prepared were characterized by X-Ray Diffraction, Transmission Electron Microscopy, adsorption/desorption of N2, Temperature Programmed Reduction, NH3 ? TPD and Atomic Absorption, and tested in the liquid phase hydrogenation of D-glucose into sorbitol in the temperature range 120–140 °C under 2.5 MPa of H2 pressure. Bimetallic catalysts with Ru:Ni ratios higher than 0.45 enhanced the catalytic behavior of the monometallic Ni/MCM-48 in the reaction, increasing the reaction rate and showing complete selectivity to sorbitol by minimizing the production of mannitol. Ru:Ni/MCM-48 (0.45) was recovered from the reaction media and tested for three reaction cycles, showing good stability under the selected experimental conditions.
- Romero, Alberto,Nieto-Márquez, Antonio,Alonso, Esther
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- AN ECO-FRIENDLY PROCESS FOR HYDROGENATION OR/AND HYDRODEOXYGENATION OF ORGANIC COMPOUND USING HYDROUS RUTHENIUM OXIDE CATALYST
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The invention discloses aneco-friendly process for hydrogenation (alkenealkene, carbonyl compound and aromatic) and hydrodeoxygenation (methoxy phenols) of organic compound using hydrous ruthenium oxide (HRO) and its supported form as a recyclable heterogeneous catalyst in aqueous medium with good yield of desired compounds (70-100%) under mild reaction conditions. The invention also discloses hydrogenation of organic compound such as alkene, carbonyl compound and substituted aromatic and also for the processes that involve hydrodeoxygenation, for example, lignin derived aromatic (methoxy phenols).
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Page/Page column 12; 20
(2017/08/01)
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- METHOD FOR PRODUCING ISOPROPANOL BY CATALYTIC CONVERSION OF CELLULOSE
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This invention provides a method for producing isopropanol from cellulose, which is characterized by: cellulose is catalytically converted to isopropanol under existence of a Cu-Cr catalyst. In the method, the Cu-Cr catalyst contains an active phase of CuCr2O4 or further contains an active phase selected from a group consisting of CuO and Cr2O3; the mass ratio of cellulose and water is 15 wt% or below; and the temperature of catalytic reaction is 200-270℃.
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Page/Page column 9
(2017/07/13)
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- Catalytic Hydrogenation of Macroalgae-Derived Alginic Acid into Sugar Alcohols
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Alginic acid, a major constituent of macroalgae, iss hydrogenated into sugar alcohols over carbon-supported noble metals for the first time. Mannitol and sorbitol are the major products of the catalytic hydrogenation of alginic acid, which consists of two epimeric uronic acids. The main reaction pathway is the consecutive hydrogenations of the aldehyde and carboxyl ends of alginic acid dimers, followed by the cleavage of the C?O?C linkage into monomeric units by hydrolysis. The highest yield of C6 sugar alcohols is 61 % (sorbitol: 29 %; mannitol: 28 %; galactitol: 4 %). The low sorbitol/mannitol ratio is in contrast to that from cellulose hydrogenation, owing to the composition of alginic acid and isomerization between sugar alcohols under the catalytic system. This new green route to producing sugar alcohols from alginic acid might provide opportunities to diversify biomass resources.
- Ban, Chunghyeon,Jeon, Wonjin,Woo, Hee Chul,Kim, Do Heui
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p. 4891 - 4898
(2017/12/07)
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- Selective C?O Bond Cleavage of Sugars with Hydrosilanes Catalyzed by Piers’ Borane Generated In Situ
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Described herein is the selective reduction of sugars with hydrosilanes catalyzed by using Piers’ borane [(C6F5)2BH] generated in situ. The hydrosilylative C?O bond cleavage of silyl-protected mono- and disaccharides in the presence of a (C6F5)2BH catalyst, generated in situ from (C6F5)2BOH, takes place with excellent chemo- and regioselectivities to provide a range of polyols. A study of the substituent effects of sugars on the catalytic activity and selectivity revealed that the steric environment around the anomeric carbon (C1) is crucial.
- Zhang, Jianbo,Park, Sehoon,Chang, Sukbok
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supporting information
p. 13757 - 13761
(2017/10/09)
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- Hormonemate Derivatives from Dothiora sp., an Endophytic Fungus
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A search for cytotoxic agents from cultures of the endophytic fungus Dothiora sp., isolated from the endemic plant Launaea arborescens, led to the isolation of six new compounds structurally related to hormonemate, with moderate cytotoxic activity against different cancer cell lines. By using a bioassay-guided fractionation approach, hormonemates A-D (1-4), hormonemate (5), and hormonemates E (6) and F (7) were obtained from the acetone extract of this fungus. Their structures were determined using a combination of HRMS, ESI-qTOF-MS/MS, 1D and 2D NMR experiments, and chemical degradation. The cytotoxic activities of these compounds were evaluated by microdilution colorimetric assays against human breast adenocarcinoma (MCF-7), human liver cancer cells (HepG2), and pancreatic cancer cells (MiaPaca_2). Most of the compounds displayed cytotoxic activity against this panel.
- Pérez-Bonilla, Mercedes,González-Menéndez, Víctor,Pérez-Victoria, Ignacio,De Pedro, Nuria,Martín, Jesús,Molero-Mesa, Joaquín,Casares-Porcel, Manuel,González-Tejero, María Reyes,Vicente, Francisca,Genilloud, Olga,Tormo, José R.,Reyes, Fernando
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p. 845 - 853
(2017/05/05)
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- Influence of the functional groups of multiwalled carbon nanotubes on performance of Ru catalysts in sorbitol hydrogenolysis to glycols
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Different functional groups (i.e. [sbnd]NH2, [sbnd]COOH, [sbnd]OH and nitrogen-doping) modified CNTs (denoted as AMCN, CMCN, HMCN and NMCN, respectively) supported ruthenium catalysts (Ru/AMCN, Ru/CMCN, Ru/HMCN and Ru/NMCN) were prepared by incipient wetness impregnation method. They were fully characterized by XRD, TG, Raman, XPS, TPD and TEM to elucidate the relationship between the physical property and their catalytic performance. TEM results shown that Ru particles were well dispersed on the surface for all the samples with the size of 1.48–1.99 nm. The effects of functional groups of carbon nanotubes (CNTs), nitrogen doping and base additive types on activity and selectivity of ethylene glycol (EG) and propylene glycol (1,2-PD) were investigated. In addition, the activity and final products distribution were much influenced by the properties of functional groups on CNTs and the type of metal cation of the base promoters, which probably participated in the reaction for accelerating a retro-aldol reaction for C[sbnd]C cleavage. Among the catalysts, Ru supported on AMCN exhibited the best catalytic activities and glycols selectivities than on MCN, CMCN, HMCN and NMCN.
- Guo, Xingcui,Dong, Huihuan,Li, Bin,Dong, Linlin,Mu, Xindong,Chen, Xiufang
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- Hydrolytic hydrogenation of cellulose in subcritical water with the use of the Ru-containing polymeric catalysts
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The study presents the results of cellulose hydrolytic hydrogenation process in subcritical water in the presence of Ru-containing catalysts based on hypercrosslinked polystyrene (HPS) MN-270 and its functionalized analogues: NH2-HPS (MN-100) and SO3H-HPS (MN-500). It was shown that the replacement of the traditional support (carbon) by HPS increases the yield of the main cellulose conversion products – polyols – important intermediates for the chemical industry. The catalysts were characterized using transmission electron microscopy (TEM), high resolution TEM, and porosity measurements. Catalytic studies demonstrated that the catalyst containing 1.0% Ru and based on MN-270 is the most active. The total yield of sorbitol and mannitol was 50% on the average at 85% cellulose conversion.
- Matveeva, Valentina G.,Sulman, Esther M.,Manaenkov, Oleg V.,Filatova, Anastasia E.,Kislitza, Olga V.,Sidorov, Alexander I.,Doluda, Valentin Yu.,Sulman, Mikhail G.,Rebrov, Evgeny V.
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- A One-Step Synthesis of C6 Sugar Alcohols from Levoglucosan and Disaccharides Using a Ru/CMK-3 Catalyst
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Sorbitol is an important commercially available chemical with a broad application range and is typically made by the catalytic hydrogenation of glucose. Here we report a high-yield synthesis of sorbitol from levoglucosan (1,6-anhydro-β-d-glucopyranose) and cellobiose, two sugars present in pyrolysis liquids, using a mesoporous carbon-supported Ru catalyst (Ru/CMK-3). The hydrogenation reactions were performed in a batch autoclave setup under a hydrogen pressure of 50 bar and temperatures ranging from 120 to 180 °C in water. The hydrogenation of levoglucosan gave essentially quantitative yields of sugar alcohols, composed of 96.2 wt % of sorbitol and 3.8 wt % of mannitol (180 °C, 5 h). Ru/CMK-3 shows superior catalytic performance compared to a commercial Ru/C catalyst. A reaction pathway involving glucose as an intermediate and subsequent (hydrogenolysis) reactions of the desired sorbitol is proposed. Reactions with glucose and sorbitol were performed to define the reaction pathways and to highlight the differences between Ru/C and Ru/CMK-3. Disaccharides including cellobiose and sucrose were also tested, yielding up to 95 wt % of C6 sugar alcohols at 180 °C in 5 h for both substrates. Detailed catalyst characterization studies (N2 physisorption, TEM, XRD, NH3-TPD, H2-TPD) revealed that Ru/CMK-3 contains considerable amounts of strong acid sites (NH3-TPD). Catalyst stability was tested by catalyst recycling experiments using levoglucosan in batch. After three successive runs, the rate of the hydrolysis reaction of LG to glucose was about constant, though the subsequent hydrogenation reaction to sorbitol/mannitol was slightly retarded as evidenced from a slight increase in the remaining amounts of glucose at the end of reaction.
- Yin, Wang,Tang, Zhenchen,Venderbosch, Robertus Hendrikus,Zhang, Zheng,Cannilla, Catia,Bonura, Giuseppe,Frusteri, Francesco,Heeres, Hero Jan
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p. 4411 - 4422
(2016/07/12)
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- Platinum-Catalyzed aqueous-Phase hydrogenation of d?Glucose to d?Sorbitol
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Aqueous-phase hydrogenation of D-glucose to D-sorbitol was systematically investigated over silica-supported Pt nanoparticles to elucidate structure?reactivity relations and mechanistic insight. D-Glucose hydrogenation over large Pt particles competes with its isomerization to D-fructose over low-coordination (electron-deficient) Pt sites; D-sorbitol production by the former process was structure insensitive for nanoparticles spanning 3?17 nm, whereas isomerization was favored by smaller particles, with both pathways independent of the choice of fumed silica or mesoporous SBA-15 support. While D-fructose was readily hydrogenated to D-mannitol under the same reaction conditions, the latter underwent minimal isomerization to D-sorbitol, which is, therefore, a direct product of D-glucose ring opening and subsequent hydrogenation of the aldose conformer. D-Sorbitol production was favored by low D-glucose concentrations (2 pressures (>40 bar), and low reaction temperatures (140 °C), which suppressed undesired polymerization side reactions.
- Zhang, Xingguang,Durndell, Lee J.,Isaacs, Mark A.,Parlett, Christopher M.A.,Lee, Adam F.,Wilson, Karen
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p. 7409 - 7417
(2018/05/23)
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- HYDROGENATION REACTION METHOD
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The present invention provides a novel hydrogenation reaction and hydrogenolysis reaction, and does not require a large scale hydrogen supply equipment and a high-pressure facility for a respective reaction. The present invention relates to a method for producing a hydrogenated compound, characterized in reducing a compound to be hydrogenated (C) using a hydrogen-containing compound (A) and a reduced compound (B) to produce the hydrogenated compound (c).
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Paragraph 0117
(2016/11/28)
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- Kinetic insight into the effect of the catalytic functions on selective conversion of cellulose to polyols on carbon-supported WO3 and Ru catalysts
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Efficient conversion of cellulose, the most abundant biomass on Earth, to chemicals in high yields remains a formidable challenge. Here, we report the marked change in the distribution of polyol products in the cellulose reaction on Ru/C and WO3/C, strongly depending on the competitive reactions of the glucose intermediate. WO3 crystallites not only promote, as a solid acid, the efficient hydrolysis of cellulose to glucose, but also catalyze the selective cleavage of the C-C bonds in glucose and other C6 sugar intermediates, leading to the formation of ethylene glycol and propylene glycol, in competition with the sugar hydrogenation to the corresponding C6 polyols (e.g. sorbitol) on Ru/C. The basic C support, behaving similar to other solid bases (i.e. MgO), catalyzes the isomerization of glucose into fructose, leading to the favored formation of propylene glycol instead of ethylene glycol. Such strong dependence of the product distribution on the catalytic functions is clarified by the kinetic analysis of the three competitive reactions of glucose, including its hydrogenation, isomerization and C-C bond cleavage. Importantly, such kinetic analysis can predict the maximum selectivity ratio of propylene glycol to ethylene glycol, which is 2.5, for example, at 478 K under the reaction conditions in this work, corresponding to a maximum yield of propylene glycol of ~71%. These understandings shed new insights into the selective conversion of cellulose, which provides guidance for the rational design of catalyst functions and tuning of reaction parameters towards the controllable synthesis of specific products from cellulose.
- Liu, Yue,Liu, Haichao
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- Hydrogenation of Aldehydes Catalyzed by an Available Ruthenium Complex
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A readily available ruthenium(II) catalyst was developed for the catalytic hydrogenation of aldehydes with a TON (turnover number) up to 340000. It can be performed without base and solvent, showing highly industrial potential. High chemoselectivity can be achieved in the presence of alkenyl and ketone groups. Further application of this protocol in glucose reduction showed good efficiency. Theoretical studies revealed that the rate-determining step is the hydrogenation step, not the carboxylate-assisted H2 activation step.
- Tan, Xuefeng,Wang, Guozhen,Zhu, Ziyue,Ren, Conghui,Zhou, Jinping,Lv, Hui,Zhang, Xiaoyong,Chung, Lung Wa,Zhang, Lina,Zhang, Xumu
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supporting information
p. 1518 - 1521
(2016/05/02)
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- Hydrolytic hydro-conversion of cellulose to ethylene glycol over bimetallic CNTs-supported NiWB amorphous alloy catalyst
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NiWB/CNTs catalysts were prepared by ultrasonic impregnation chemical reduction method and showed high activity in the hydrolytic hydro-conversion of cellulose to ethylene glycol. The conversion of cellulose could be high to 100% with an ethylene glycol s
- Liu, Haili,Qin, Lin,Wang, Xiaoyue,Du, Changhai,Sun, De,Meng, Xiangchun
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- Method for preparing sorbitol from cellulose
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The invention relates to a method for preparing sorbitol through cellulose hydrolysis and hydrogenation. The method comprises that under carbon dioxide pressure of 0.1-3MPa, in the presence of a hydrogen mesoporous ZSM-5 zeolite-loaded Pt-Ni catalyst, under conditions of a temperature of 230-250 DEG C and H2 pressure of 0.5-6 MPa, sorbitol is prepared through cellulose hydrolysis and hydrogenation, wherein a sorbitol yield is 53.2% and a ratio of sorbitol to sorbitol isomer mannitol is greater than 12, and after the reaction, carbon dioxide spontaneously separates from the liquid product. The method is free of a liquid inorganic acid so that acid pollution and equipment corrosion are avoided. The method solves the problem that a sorbitol yield is low at a high reaction temperature of 230-250 DEG C, realizes rapid cellulose conversion and improves a sorbitol yield.
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Paragraph 0019; 0020
(2017/06/20)
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- Continuous transfer hydrogenation of sugars to alditols with bioderived donors over Cu-Ni-Al catalysts
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The transfer hydrogenation of sugars to alditols with biobased alcohol donors was studied over hydrotalcite-derived Cu6-xNixAl2 catalysts prepared by coprecipitation at different pH and featuring variable Cu/Ni ratios. Their evaluation, after in situ activation in pure H2 at 773 K, in the ethanol-assisted upgrading of glucose in a continuous-flow fixed-bed reactor identified the solid synthesized at pH 9-10 and with Cu/Ni=1 as the best performer. Based on textural, structural, and redox analyses, this is related to an enhanced intermetallic interaction. Upon screening alternative donors, a sorbitol yield as high as 67 % was achieved with 1,4-butanediol. The catalytic system displayed a stable behavior during 48 h on stream and proved suitable to hydrogenate also fructose, mannose, xylose, and arabinose to the corresponding polyols (yields up to 65 %), thus standing as a more sustainable and economical alternative to Ru-based catalysts for sugar reductive upgrading. Finding the right partner: Hydrotalcite-derived Cu-Ni-Al materials efficiently catalyze the continuous transfer hydrogenation of C6 and C5 sugars with biobased alcohols as hydrogen donors with yields of up to 67 %. This technology comprises a safer and cheaper alternative to direct hydrogenation over Ru catalysts.
- Scholz, David,Aellig, Christof,Mondelli, Cecilia,Pérez-Ramírez, Javier
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p. 1551 - 1558
(2015/05/27)
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- Structure sensitivity in catalytic hydrogenation of glucose over ruthenium
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The structure sensitivity was studied in the hydrogenation of glucose to sorbitol over supported ruthenium catalysts in a semi-batch reactor. Ruthenium on carbon supports with different ruthenium particle sizes was prepared and evaluated in the hydrogenation experiments. The highest turnover frequency was obtained with a catalyst bearing average ruthenium particle size of ca. 3 nm.
- Aho, Atte,Roggan, Stefan,Simakova, Olga A.,Salmi, Tapio,Murzin, Dmitry Yu.
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p. 195 - 199
(2015/03/14)
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- One-pot catalytic conversion of cellulose into polyols with Pt/CNTs catalysts
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A series of Pt nanoparticles supported on carbon nanotubes (CNTs) were synthesized using the incipient-wetness impregnation method. These catalysts were characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscope (TEM) techniques. The characterization results indicate that the Pt nanoparticles were highly dispersed on the surface of the CNTs, and the mean size was less than 5 nm. These catalysts were utilized to convert cellulose to hexitol, ethylene glycerol (EG), and 1,2-propylene glycol (1,2-PG) under low H2 pressure. The total yields were as high as 71.4% for EG and 1,2-PG using 1 Pt/CNTs as the catalyst in the hydrolytic hydrogenation of cellulose under mild reaction conditions.
- Yang, Li,Yan, Xiaopei,Wang, Qiwu,Wang, Qiong,Xia, Haian
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supporting information
p. 87 - 92
(2015/03/05)
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- Nano Ru catalysts supported on carbon nanotubes for cellobiose conversion to sugar alcohols: Effects of CNT channel size
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Ruthenium (Ru) nanoparticles (NPs) were supported on the interior surface of carbon nanotubes (CNTs) with different inner diameters to study the effects of CNT channel size on the cellobiose conversion. It was found that the reducibility and catalytic activity of Ru/CNT-in sample was enhanced with the decrease of the carbon channel size and Ru/CNTs-in catalysts showed significantly higher catalytic activities than that of the Ru/CNTs-out sample. The confinement effect of the CNT channel was gradually enhanced with the decrease of the nanotube channel size (inner diameter). The encapsulation of Ru NPs inside the CNT channels improved the Ru reducibility and decreased the leaching of catalytic sites.
- Ran, Maofei,Chu, Wei,Liu, Yan,Borgna, Armando
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p. 103669 - 103673
(2015/12/23)
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- Catalytic conversion of glucose and cellobiose to ethylene glycol over Ni-WO3/SBA-15 catalysts
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Hydrogenolysis of glucose and cellobiose, used as the model feedstocks, over Ni-WO3/SBA-15 catalysts has been investigated to probe the influencing factors for the conversion of cellulose to ethylene glycol (EG). The conversion of glucose and cellobiose to EG showed different dependencies on reaction temperature; a lower reaction temperature was needed for the former. Additionally, the surface atomic ratio of W to Ni on the Ni-WO3/SBA-15 catalysts was the key factor for the product distribution. Both glucose and cellobiose had their own optimum W-Ni ratio for the production of EG, and the ratio of W to Ni for glucose was slightly lower than that of cellobiose. On the other hand, the Ni-WO3/SBA-15 catalysts were thoroughly characterized by N2 adsorption-desorption, X-ray diffraction (XRD), hydrogen-temperature programmed reduction (H2-TPR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results indicated that the reducibility of Ni-WO3/SBA-15 catalysts with high Ni loading was more similar to that of pure NiO. More importantly, the change of surface atomic content of Ni and W of Ni-WO3 catalysts with various Ni loadings resulted from the surface W species of the catalysts being gradually covered by Ni species with the increase of Ni loading.
- Cao, Yueling,Wang, Junwei,Kang, Maoqing,Zhu, Yulei
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p. 90904 - 90912
(2015/11/16)
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- Remarkable effect of extremely dilute H2SO4 on the cellulose conversion to ethylene glycol
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Cellulose is the most abundant biomass in nature, and its catalytic conversion to commodity chemical ethylene glycol represents an important advance towards sustainable chemistry. In previous work, we have shown that tungstic acid plays a key role in selective C-C cleavage to form glycolaldehyde and then ethylene glycol. To further enhance the efficiency of tungstic acid, a series of additives were investigated in this work. Among various acid additives, H2SO4 stands out as the most remarkable additive; ethylene glycol yield was enhanced from 32.6% to 52.6% at a H2SO4/H2WO4 molar ratio of 0.03 and a H2WO4/cellulose weight ratio of 0.05, that is, an extremely dilute acid concentration. Weakly acidic sulfates (e.g., CuSO4 and FeSO4) have also been demonstrated to be highly efficient additives to improve the catalytic efficiency of tungstic acid, through promoting the hydrolysis of cellulose.
- Xu, Gang,Wang, Aiqin,Pang, Jifeng,Zheng, Mingyuan,Yin, Jianzhong,Zhang, Tao
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- Versatile nickel-lanthanum(III) catalyst for direct conversion of cellulose to glycols
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Using cellulosic biomass to synthesize bulk quantities of high-value chemicals is of great interest for developing a sustainable biobased society. Especially, direct catalytic conversion of cellulose to glycols, important building blocks for polymers, remains a grand challenge. Herein, we report the development of a versatile binary nickel-lanthanum(III) catalyst for the conversion of cellulose to both ethylene glycol (EG) and propylene glycol (1,2-PG) in a yield of 63.7%, which is one of the best performances reported for this catalytic reaction. Especially, lanthanum(III) exhibited a high level of activity toward the degradation of cellulose (TON = 339) at a very low concentration (0.2 mmol/L). On the basis of density functional theory calculations and experimental analyses, we addressed a dual route for this catalytic mechanism: a major route involving the selective cracking of sugars into C2 molecules and a minor route involving the hydrogenolysis of sugar alcohols. Lanthanum(III) catalyzes the cleavage of the C2-C3 bond in glucose via sequential epimerization and 2,3-hydride shift reactions to form glycolaldehyde, the precursor of EG.
- Sun, Ruiyan,Wang, Tingting,Zheng, Mingyuan,Deng, Weiqiao,Pang, Jifeng,Wang, Aiqin,Wang, Xiaodong,Zhang, Tao
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p. 874 - 883
(2015/03/04)
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