- THE PAIRED ELECTROCHEMICAL SYNTHESIS OF GLUCONIC ACID AND SORBITOL
-
Gluconic acid and sorbitol are obtained simultaneously both with 90percent yields by paired electolysis of glucose, with a Pb sheet cathode and a dimension stable anode (DSA) in a press filtration diaphragm cell.The anolyte is composed from 66.7percent glucose and 2percent NaBr, and the catholyte from 66.7percent glucose and 2.5percent Na2SO4, respectively.The electrolysis was performed at the temperature of 60 deg C, at the current density of 50 mA cm-2, Qr is 110percent.At this optimum conditions the current efficiencies for both gluconic acid and sorbitol are higher than 80percent.
- Li, Hongmei,Li, Wei,Guo, Zicheng,Gu, Dengping,Cai, Shengmin,Fujishima, Akira
-
-
Read Online
- Structure of a marsupial-mild trisaccharide.
-
A trisaccharide, which is a major carbohydrate component of the milk of the tammar wallaby and the grey kangaroo, has been identified by chemical, enzymic, g.l.c.-m.s., and n.m.r. methods as O-beta-D-galactopyranosyl-(1 yields 3)-O-beta-D-galactopyranosyl-(1 yields 4)-D-glucose (3'-galactosyl-lactose).
- Messer,Trifonoff,Stern,Collins,Bradbury
-
-
Read Online
- Bimetallic Ru:Ni/MCM-48 catalysts for the effective hydrogenation of D-glucose into sorbitol
-
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
-
-
Read Online
- A Robust and Highly Selective Catalytic System of Copper–Silica Nanocomposite and 1-Butanol in Fructose Hydrogenation to Mannitol
-
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
-
-
Read Online
- Transfer hydrogenation of cellulose to sugar alcohols over supported ruthenium catalysts
-
Ru/C catalysts are active for the conversion of cellulose using 2-propanol or H2 of 0.8 MPa as sources of hydrogen, whereas the Ru/Al 2O3 catalyst is inactive in both reactions, indicating that the Ru/C catalysts are remarkably effective for the cellulose conversion.
- Kobayashi, Hirokazu,Matsuhashi, Hisateru,Komanoya, Tasuku,Hara, Kenji,Fukuoka, Atsushi
-
-
Read Online
- Chemical analysis of new water-soluble (1→6)-, (1→4)-α, β-glucan and water-insoluble (1→3)-, (1→4)-β-glucan (Calocyban) from alkaline extract of an edible mushroom, Calocybe indica (Dudh Chattu)
-
Two different glucans (PS-I, water-soluble; and PS-II, water-insoluble) were isolated from the alkaline extract of fruit bodies of an edible mushroom Calocybe indica. On the basis of acid hydrolysis, methylation analysis, periodate oxidation, and NMR anal
- Mandal, Soumitra,Maity, Kankan K.,Bhunia, Sanjoy K.,Dey, Biswajit,Patra, Sukesh,Sikdar, Samir R.,Islam, Syed S.
-
-
Read Online
- Structural characterization and anti-inflammatory activity of a linear β-d-glucan isolated from Pleurotus sajor-caju
-
Glucans comprise an important class of polysaccharides present in basidiomycetes with potential biological activities. A (1 → 3)-β-d-glucan was isolated from Pleurotus sajor-caju via extraction with hot water followed by fractionation by freeze-thawing and finally by dimethyl sulfoxide extraction. The purified polysaccharide showed a 13C-NMR spectrum with six signals consisting of a linear glucan with a β-anomeric signal at 102.8 ppm and a signal at 86.1 ppm relative to O-3 substitution. The other signals at 76.2, 72.9, 68.3, and 60.8 ppm were attributed to C5, C2, C4, and C6, respectively. This structure was confirmed by methylation analysis, and HSQC studies. The β-d-glucan from P. sajor-caju presented an immunomodulatory activity on THP-1 macrophages, inhibited the inflammatory phase of nociception induced by formalin in mice, and reduced the number of total leukocytes and myeloperoxidase levels induced by LPS. Taken together, these results demonstrate that this β-d-glucan exhibits a significant anti-inflammatory activity.
- Silveira, Marcia L.L.,Smiderle, Fhernanda R.,Moraes, Carla Porto,Borato, Débora G.,Baggio, Cristiane H.,Ruthes, Andrea Caroline,Wisbeck, Elisabeth,Sassaki, Guilherme L.,Cipriani, Thales R.,Furlan, Sandra A.,Iacomini, Marcello
-
-
Read Online
- Isolation and characterization of non-sulfated and sulfated triterpenoid saponins from Fagonia indica
-
Seven previously undescribed, sulfated triterpenoid glycosides, named nayabin A-G along with a known triterpenoid glycoside were isolated from the whole plant of Fagonia indica. Their structures were elucidated through spectral studies including 1D- (1H and 13C), 2D-NMR spectroscopy (HSQC, HMBC, COSY and NOESY), and mass spectrometry (ESI-MS/MS). β-D-Glucopyranosyl 3β-hydroxy-23-O-β-D-glucopyranosyloxy-taraxast-20-en-28-oate, a known compound exerts glucose-dependent insulin secretory activity, which seems to exhibit a decreased risk of drug-induced hypoglycemia and may offer distinct advantages as anti-diabetic agent.
- Kanwal, Nayab,Adhikari, Achyut,Hameed, Abdul,Hafizur, Rahman M.,Musharraf, Syed Ghulam
-
-
Read Online
- Pt nanocatalysts supported on reduced graphene oxide for selective conversion of cellulose or cellobiose to sorbitol
-
Pt nanocatalysts loaded on reduced graphene oxide (Pt/RGO) were prepared by means of a convenient microwave-assisted reduction approach with ethylene glycol as reductant. The conversion of cellulose or cellobiose into sorbitol was used as an application reaction to investigate their catalytic performance. Various metal nanocatalysts loaded on RGO were compared and RGO-supported Pt exhibited the highest catalytic activity with 91.5 % of sorbitol yield from cellobiose. The catalytic performances of Pt nanocatalysts supported on different carbon materials or on silica support were also compared. The results showed that RGO was the best catalyst support, and the yield of sorbitol was as high as 91.5 % from cellobiose and 58.9 % from cellulose, respectively. The improvement of catalytic activity was attributed to the appropriate Pt particle size and hydrogen spillover effect of Pt/RGO catalyst. Interestingly, the size and dispersion of supported Pt particles could be easily regulated by convenient adjustment of the microwave heating temperature. The catalytic performance was found to initially increase and then decrease with increasing particle size. The optimum Pt particle size was 3.6 nm. These findings may offer useful guidelines for designing novel catalysts with beneficial catalytic performance for biomass conversion. Support group: Pt nanocatalysts loaded on reduced graphene oxide are prepared by a microwave-assisted ethylene glycol reduction method, and present high activity and selectivity for the conversion of cellobiose or cellulose to sorbitol. The high catalytic activity is attributed to the synergistic effects of reduced graphene oxide and the supported Pt nanoparticles.
- Wang, Ding,Niu, Wenqi,Tan, Minghui,Wu, Mingbo,Zheng, Xuejun,Li, Yanpeng,Tsubaki, Noritatsu
-
-
Read Online
- Glucose Hydrogenation to Sorbitol over a Skeletal Ni-P Amorphous Alloy Catalyst (Raney Ni-P)
-
A skeletal Ni-P amorphous alloy catalyst (Raney Ni-P) was prepared by alkali leaching of a Ni-Al-P amorphous precursor obtained by the rapid quenching technique of a melting solution containing Ni, Al, and P. This catalyst showed higher turnover rates (per surface Ni atom) than Raney Ni for the hydrogenation of glucose to sorbitol, apparently as a result of promotion of Ni-active sites by phosphorus. The Raney Ni-P catalysts gave turnover rates similar to those measured on Ni-P amorphous alloys without Al, but they had a significantly higher density of Ni surface atoms. As a result, Raney Ni-P catalysts showed superior specific hydrogenation rates (per gram catalyst) than either Raney Ni or Ni-P amorphous alloys.
- Li, Hexing,Wang, Weijiang,Fa Deng, Jing
-
-
Read Online
- Crystallization and properties of NADPH-dependent L-sorbose reductase from Gluconobacter melanogenus IFO 3294
-
NADPH-Dependent L-sorbose reductase (SORD, synonimously NADP-dependent D-sorbitol dehydrogenase) was purified and crystallized for the first time from the cytosolic fraction of Gluconobacter melanogenus IFO 3294. The enzyme catalyzed oxidoreduction between D-sorbitol and L-sorbose in the presence of NADP or NADPH. Affinity chromatography by a Blue-dextran Sepharose 4B column was effective for purifying the enzyme giving about 770-fold purification with an overall yield of more than 50%. The crystalline enzyme showed a single sedimentation peak in analytical ultracentrifugation, giving an apparent sedimentation constant of 3.8 s. Gel filtration on a Sephadex G-75 column gave the molecular mass of 60 kDa to the enzyme, which dissociated into 30 kDa subunit on SDS-PAGE, indicating that the enzyme is composed of 2 identical subunits. Reduction of L-sorbose to D-sorbitol predominated in the presence of NADPH with the optimum pH of 5.0-7.0. Oxidation of D-sorbitol to L-sorbose was observed in the presence of NADP at the optimum pH of 7.0-9.0. The relative rate of L-sorbose reduction was more than seven times higher to that of D-sorbitol oxidation. NAD and NADH were inert for both reactions. D-Fructose reduction in the presence of NADPH did not occur with SORD. Since the reaction rate in L-sorbose reduction highly predominated over D-sorbitol oxidation over a wide pH range, the enzyme could be available for direct enzymatic measurement of L-sorbose. Even in the presence of a large excess of D-glucose and other substances, oxidation of NADPH to NADP was highly specific and stoichiometric to the L-sorbose reduced. Judging from the enzymatic properties, SORD would contribute to the intracellular assimilation of L-sorbose incorporated from outside the cells where L-sorbose is accumulated in huge amounts in the culture medium.
- Adachi, Osao,Ano, Yoshitaka,Moonmangmee, Duangtip,Shinagawa, Emiko,Toyama, Hirohide,Theeragool, Gunjana,Lotong, Napha,Matsushita, Kazunobu
-
-
Read Online
- Glucose hydrogenation in a trickle-bed reactor
-
Catalytic hydrogenation of 40% aqueous solutions of D-glucose to D-glucitol was studied in a high-pressure trickle-bed reactor. The reactions were performed on a supported nickel catalyst at temperatures ranging from 115 to 165°C and in the pressure range 0.5 to 10 MPa. The order of the reaction with respect to hydrogen is 0.65 and apparent activation energy 23.8-48.5 kJ mol-1, the latter depending on initial molar glucose concentration and density and viscosity of the solution. The influence of external diffusion is necessary to take into account for scaling-up the process.
- Tukac, Vratislav
-
-
Read Online
- Surface modification of SiO2 for highly dispersed Pd/SiO2 Catalyst
-
Surface modification of SiO2 supports was shown to significantly affect the properties of Pd/SiO2 catalysts. The surface of SiO2 can be modified by various pretreatment methods. In this study, the effect of different calcination temperatures on support surface was investigated. Pd supported on pretreated SiO2 was characterized by H2 temperature-programmed reduction (TPR), XRD, CO chemisorption measurements, and field-emission transmission electron microscopy (FE-TEM). The silanol group (-OH), which is one of the functional groups of SiO2, interferes with the reduction of palladium because it strongly bonds with palladium ions (-PdO) during the preparation of the catalyst. Due to the complete removal of silanol (Si-OH) groups following calcination at 700 °C, the metal reducibility was enhanced, and the catalyst pretreated at this calcination temperature exhibited the highest metal dispersion of 13.02%. Further, to confirm the catalytic activity of the prepared catalysts, hydrogenation of D-glucose was conducted. The HPLC results demonstrated that Pd/SiO2-700 has the highest catalytic activity toward hydrogenation of D-glucose. Therefore, it was confirmed that the removal of silanol groups increase the metal dispersion and catalytic activity of Pd/SiO2 catalyst.
- Kwon, Ji Soo,Kim, Ji Sun,Lee, Hak Sung,Lee, Man Sig
-
-
Read Online
- Efficient conversion of D-glucose into D-sorbitol over MCM-41 supported Ru catalyst prepared by a formaldehyde reduction process
-
Ru/MCM-41 catalyst prepared by an impregnation-formaldehyde reduction method showed higher catalytic activity and sorbitol selectivity than other catalysts in the hydrogenation of glucose. SEM and XRD indicated the partial surface properties of Ru/MCM-41. Moreover, Ru dispersion and Ru surface area of Ru/MCM-41 were determined by pulse chemisorption, and the result further proved that Ru/MCM-41 had higher catalytic activity. A catalyst recycling experiment demonstrated that Ru/MCM-41 was a better catalyst and it could be reused three or four times. A speculated mechanism was proposed to illustrate the detailed process of d-glucose hydrogenation to produce sorbitol.
- Zhang, Jun,Lin, Lu,Zhang, Junhua,Shi, Jianbin
-
-
Read Online
- Role OfTiO2 pillared bentonit and catalyst nickel for hydrogenation glucose to generate sorbitol
-
Glucose hydrogenation using water at solvent was happened trough two step. First, water was reduced to hydrogen and oxygen gases by TiO2 pillared bentonite. Second, hydrogen that produced was used to reduce glucose into sorbitol. The reaction was prepared in transpaharan medium for 30 days along under UV from sunlight. The product of reaction was characterized using SEM, XRD, FTIR and DSC.
- Supeno, Minto,Nurhaidapasaribu,Siburian, Rikson
-
-
Read Online
- Ru/P-containing porous biochar-efficiently catalyzed cascade conversion of cellulose to sorbitol in water under medium-pressure H2 atmosphere
-
This paper discloses a simple and productive strategy for the preparation of biochar-based bifunctional catalysts. In this strategy, very cheap bamboo powder is thermally carbonized to yield P-containing porous biochars (PBCs) by the activation of concentrated phosphoric acid (H3PO4), and the latter can be transformed into the target catalysts via loading Ru nanometer particles (NPs) on them (marked as Ru/PBCs). A series of characterizations and measurements support that PBCs have stable and rich micro-meso pores and small strong acidic protons (0.100.28 mmol￠g11) attributable to the grafted and/or skeleton phosphorus groups, as well as a strong affinity to β-1,4-glycosidic bonds, thus exhibiting a good acid catalytic activity for the hydrolysis of cellulose to glucose. More importantly, they are excellent acidic supports for the loading of Ru NPs owing to high BET surface area, which can give the loaded Ru NPs uniform and narrow distribution (16 nm). The resulting bifunctional Ru/PBCs catalysts possess excellent hydrolytic hydrogenating activity for the one-pot cascade conversion of cellulose and the optimized conditions can achieve ca. 89% hexitol yield with 98% sorbitol selectivity under relatively mild conditions. This work provides a good example for the preparation of biomass-derived bifunctional catalysts and their applications in biorefinery.
- Chen, Shuainan,Fu, Zaihui,Jiang, Dabo,Liu, Yachun,Mao, Feng,Wan, Feifei,Xiong, Manman,Yang, Long,Zhang, Chao,Zhang, Qiao
-
-
Read Online
- Biochemical composite synthesized by stepwise crosslinking: An efficient platform for one-pot biomass conversion
-
This paper describes the development of a new bifunctional catalyst system that integrates enzyme and chemical material into a biochemical composite through a stepwise crosslinking approach. The as-prepared biochemical composite not only allows one-pot biomass conversion via sequential enzyme-catalyzed hydrolysis of biomass materials to glucose and metal-catalyzed hydrogenation of glucose to sorbitol, but also enables reusability of the catalyst. This design concept facilitates access to fuels and chemicals from the biomass-derived sorbitol and will attract more attention in the foreseeable future.
- Wei, Wei,Wang, Cong,Zhao, Yu,Peng, Shichao,Zhang, Haoyang,Bian, Yipeng,Li, Hexing,Zhou, Xinggui,Li, Hui
-
-
Read Online
- The effect of physical morphology and the chemical state of Ru on the catalytic properties of Ru-carbon for cellulose hydrolytic hydrogenation
-
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
-
-
Read Online
- Selective hydrogenation of D-glucose using amine functionalized nanoporous polymer supported Ru nanoparticles based catalyst
-
Amine functionalized nanoporous polymer (AFPS) supported Ru based catalysts were prepared by simple impregnation-chemical reduction method, wherein Ru nanoparticles dispersed on AFPS matrix. The synthesized Ru/AFPS catalysts with different Ru loading were characterized by various characterization tools such as powder XRD, HRTEM, SEM, FTIR, TGA, CO chemisorption and XPS. The catalytic performances of Ru/AFPS catalysts were evaluated in hydrogenation of D-glucose to produce D-sorbitol under aqueous phase condition. The experiments results indicated that the increase of Ru content in Ru/AFPS catalyst enhanced the formation of desire D-sorbitol and 5Ru/AFPS catalyst (having 5 wt% of Ru) showed higher conversion and high D-sorbitol selectivity (98%). In comparison to non-functionalized polymer supported Ru catalyst (5Ru/PS), the catalyst 5Ru/AFPS exhibited higher catalyst performance. The achieved TOF with 5Ru/AFPS is almost 2.5 times higher than 5Ru/PS. The catalyst nanoporous structure with wide range of pores, high specific surface area and the presence of functional group on surface are considered to be responsible for observed higher catalyst performance of 5Ru/AFPS. Moreover, the effects of reaction temperature, hydrogen pressure and reaction time on conversion and selectivity of D-glucose hydrogenation were studied and the catalyst was also reused.
- Dabbawala, Aasif A.,Mishra, Dinesh K.,Hwang, Jin-Soo
-
-
Read Online
- Structural features and antioxidant activity of a new galactoglucan from edible mushroom Pleurotus djamor
-
A new water soluble galactoglucan with apparent molecular weight ~1.61 × 105 Da, was isolated from the edible mushroom Pleurotus djamor by hot water extraction followed by purification through dialysis tubing cellulose membrane and sepharose 6B column chromatography. The sugar analysis showed the presence of glucose and galactose in a molar ratio of nearly 3:1 respectively. The structure of the repeating unit in the polysaccharide was determined through chemical and NMR experiments as:[Formula presented] In vitro antioxidant studies showed that the PDPS exhibited hydroxyl radical scavenging activity (EC50 = 1.681 ± 0.034 mg/mL), DPPH radical scavenging activity (EC50 = 3.83 ± 0.427 mg/mL), reducing power (EC50 = 4.258 ± 0.095 mg/mL), and ABTS radical quenching activity (EC50 = 0.816 ± 0.077 mg/mL). So, PDPS should be explored as a natural antioxidant.
- Maity, Gajendra Nath,Maity, Prasenjit,Khatua, Somanjana,Acharya, Krishnendu,Dalai, Sudipta,Mondal, Soumitra
-
-
Read Online
- Conversion of cellulose and cellobiose into sorbitol catalyzed by ruthenium supported on a polyoxometalate/metal-organic framework hybrid
-
Cellulose and cellobiose were selectively converted into sorbitol over water-tolerant phosphotungstic acid (PTA)/metal- organic-framework-hybrid- supported ruthenium catalysts, Ru-PTA/MIL-100(Cr), under aqueous hydrogenation conditions. The goal was to investigate the relationship between the acid/metal balance of bifunctional catalysts Ru-PTA/MIL-100(Cr) and their performance in the catalytic conversion of cellulose and cellobiose into sugar alcohols. The control of the amount and strength of acid sites in the supported PTA/MIL-100(Cr) was achieved through the effective control of encapsulated-PTA loading in MIL-100(Cr). This design and preparation method led to an appropriately balanced Ru-PTA/MIL-100(Cr) in terms of Ru dispersion and hydrogenation capacity on the one hand, and acid site density of PTA/MIL-100(Cr) (responsible for acid-catalyzed hydrolysis) on the other hand. The ratio of acid site density to the number of Ru surface atoms (nA/n Ru) of Ru-PTA/MIL-100(Cr) was used to monitor the balance between hydrogenation and hydrolysis functions; the optimum balance between the two catalytic functions, that is, 8.84A/nRu12.90, achieves maximum conversion of cellulose and cellobiose into hexitols. Under the applied reaction conditions, optimal results (63.2 % yield in hexitols with a selectivity for sorbitol of 57.9 % at complete conversion of cellulose, and 97.1 % yield in hexitols with a selectivity for sorbitol of 95.1 % at complete conversion of cellobiose) were obtained using a Ru-PTA/MIL-100(Cr) catalyst with loadings of 3.2 wt % for Ru and 16.7 wt % for PTA. This research thus opens new perspectives for the rational design of acid/metal bifunctional catalysts for biomass conversion. Acid/Metal Balance: Bifunctional catalysts containing ruthenium and polyoxometalates as active species with a metal-organic framework as support and encapsulation matrix, respectively, are synthesized. Excellent yields in sorbitol are obtained in the conversion of cellobiose and ball-milled cellulose. The evaluation of the balance between the hydrogenation and hydrolysis functions of these bifucntional catalysts reveals that by carefully balancing the ratio of acid site density and the number of metal surface atoms a maximum conversion can be achieved. Copyright
- Chen, Jinzhu,Wang, Shengpei,Huang, Jing,Chen, Limin,Ma, Longlong,Huang, Xing
-
-
Read Online
- Kinetic study of catalytic conversion of cellulose to sugar alcohols under low-pressure hydrogen
-
Efficient hydrolytic hydrogenation of cellulose to sugar alcohols under low H2 pressures has remained a challenge. This article deals with the conversion of cellulose by using a carbon-supported Ru catalyst under H 2 pressures as low as 0.7-0.9 MPa (absolute pressure at room temperature). Kinetic studies revealed that the Ru catalyst not only enhances the hydrolysis of cellulose to glucose and hydrogenation of glucose to sugar alcohols (sorbitol and mannitol), but also the degradation of sugar alcohols to C2-C6 polyols and gasses. The degradation path limits the total yield of sugar alcohols to less than 40 %. The yield of sugar alcohols is theoretically improved by increasing the ratio of the reaction rates of the cellulose hydrolysis, which is the rate-determining step in the reaction, to the decomposition. Thus, a mix-milling pretreatment of cellulose and the Ru catalyst together selectively accelerated the hydrolysis step and raised the yield up to 68 %, whereas the addition of acids in the cellulose conversion was less effective as a result of promotion of side-reactions. These results demonstrate superior applicability of the mix-milling treatment in the depolymerization of cellulose to its monomers. Copyright
- Komanoya, Tasuku,Kobayashi, Hirokazu,Hara, Kenji,Chun, Wang-Jae,Fukuoka, Atsushi
-
-
Read Online
- Conversion of cellobiose into sorbitol in neutral water medium over carbon nanotube-supported ruthenium catalysts
-
Carbon nanotube (CNT)-supported ruthenium catalysts were studied for the hydrogenation of cellobiose in neutral water medium. The acidity of catalysts and the size of Ru particles played key roles in the conversion of cellobiose to sorbitol. A higher concentration of nitric acid used for CNT pretreatment provided a better sorbitol yield, suggesting an important role of catalyst acidity. The catalysts with larger mean sizes of Ru particles and abundant acidic sites exhibited better sorbitol yields, while those with smaller Ru particles and less acidic sites favored the formation of 3-β-d-glucopyranosyl-d-glucitol. We elucidated that cellobiose was first converted to 3-β-d-glucopyranosyl-d-glucitol via the hydrogenolysis, and then sorbitol was formed through the cleavage of β-1,4-glycosidic bond in 3-β-d-glucopyranosyl-d-glucitol over the catalysts. The catalyst with smaller Ru particles favored the first step but was disadvantageous to the second step due to the less acidity. Smaller Ru particles also accelerated the degradation of sorbitol.
- Deng, Weiping,Liu, Mi,Tan, Xuesong,Zhang, Qinghong,Wang, Ye
-
-
Read Online
- Hydrogenation of glucose over reduced Ni/Cu/Al hydrotalcite precursors
-
Ni/Cu/Al hydrotalcite precursors were synthesized by a co-precipitation method. The activity of the reduced precursors for hydrogenation of glucose to sorbitol was tested. The effects of preparation methods and activation treatment on the performance of the obtained catalysts were investigated in detail. XRD and XPS tests provided the essential properties of the precursors and prepared catalysts. The properly high reduction temperature could obviously enhance catalyst activity. The conversion of glucose and selectivity to sorbitol on Ni1.85Cu1Al1.15 catalyst at 398 K were 78.4 and 93.4 %, respectively.
- Zhang, Jun,Wu, Shubin,Liu, Ying,Li, Bo
-
-
Read Online
- Polyoxometalate-supported ruthenium nanoparticles as bifunctional heterogeneous catalysts for the conversions of cellobiose and cellulose into sorbitol under mild conditions
-
Ru nanoparticles loaded on a Keggin-type polyoxometalate (Cs 3PW12O40), which did not possess strong intrinsic acidity, efficiently catalysed the conversions of cellobiose and cellulose into sorbitol in water medium in H2 at ≤433 K. The Bronsted acid sites generated in situ from H2 have been demonstrated to play a key role in the formation of sorbitol. The Royal Society of Chemistry 2011.
- Liu, Mi,Deng, Weiping,Zhang, Qinghong,Wang, Yanliang,Wang, Ye
-
-
Read Online
- Catalytic conversion of cellulose into sugar alcohols
-
Sweetly done: Pt or Ru catalysts supported on inorganic oxides show high activity for the conversion of cellulose into sugar alcohols (mainly sorbitol) in water under hydrogen pressure; furthermore, the catalysts can be recycled over repeated runs. Glucose is produced in low yields, thus suggesting that the Pt (or Ru)/oxide works as a bifunctional catalyst for the hydrolysis of cellulose and subsequent reduction to sugar alcohols. (Figure Presented).
- Fukuoka, Atsushi,Dhepe, Paresh L.
-
-
Read Online
- Procedure for reducing D-arabino-hexosulose to a mannitol rich mixture of D-mannitol and D-glucitol
-
D-arabino-Hexosulose (D-glucosone, 2) can now be conveniently produced by the enzymic reaction of pyranose-2-oxidase (P2O) with D-glucose (1).D-arabino-Hexosulose has been efficiently and selectively reduced to D-fructose (3) by catalytic hydrogenation with palladium on carbon.We now report a procedure for reducing (2) to a mannitol-rich mixture of D-mannitol (4) and D-glucitol (sorbitol, 5).The method uses catalytic hydrogenation with Raney nickel, and yields 4 and 5 in 3:1 ratio.This ratio is unlike that obtained by catalytic hydrogenation of D-glucose (which yields exclusively D-glucitol) or by catalytic hydrogenation of D-fructose (which yields 4 and 5 in 1:1 ratio).
- Moreland, Margaret,Wadsworth, Julie,Geigert, John,Neidleman, Saul L.
-
-
Read Online
- Ru-B amorphous alloy deposited on mesoporous silica nanospheres: An efficient catalyst for d-glucose hydrogenation to d-sorbitol
-
In this paper, highly ordered mesoporous silica nanospheres externally covered by methyl groups (-CH3) but internally grafted by aminopropyl groups (-NH2) were used as host matrix for loading Ru-B amorphous alloy nanoparticles (NPs). The -NH2 and the -CH3 groups served synergistically as effective functionalities for highly dispersing Ru-B NPs within the pore channels of the mesoporous host. Such catalyst was used in the liquid-phase d-glucose hydrogenation and delivered much higher activity than industrial Raney Ni and the commercial Ru/C catalysts. Meanwhile, it could be used repetitively for more than 9 times, showing a good potential in practical applications. This work demonstrated that the surface properties of mesoporous materials can be modified through region-selective immobilization of diverse organic groups, which is essential to optimize the catalysis for some reactions.
- Wang, Senlin,Wei, Wei,Zhao, Yu,Li, Hexing,Li, Hui
-
-
Read Online
- Selective hydrogenation of d-glucose to d-sorbitol over HY zeolite supported ruthenium nanoparticles catalysts
-
HY zeolite (HYZ) supported ruthenium (Ru) nanoparticles catalyst (Ru/HYZ) is prepared by simple impregnation method and is characterized by using energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), CO chemisorption and inductively coupled plasma (ICP) mass spectrometry. The catalyst Ru/HYZ is evaluated in hydrogenation of d-glucose and hydrogenation experiments to produce a selective product d-sorbitol were conducted batch wise in a three-phase laboratory scale reactor. The kinetics studies of d-glucose hydrogenation using the catalyst Ru/HYZ were carried out. In the operating regime studied the rate of reaction showed first orders dependency with respect to d-glucose and hydrogen. For affording maximum d-glucose conversion, yield and selectivity to d-sorbitol, the reaction conditions were also optimized.
- Mishra, Dinesh Kumar,Dabbawala, Aasif Asharaf,Park, Jung Je,Jhung, Sung Hwa,Hwang, Jin-Soo
-
-
Read Online
- Structural Characterization and Immunostimulatory Activity of Polysaccharides from Brassica rapa L.
-
Two neutral polysaccharides (BRNP-1, 6.9 kDa; BRNP-2, 4.8 kDa) were purified from the common edible plant Brassica rapa L. via the combined techniques of ion-exchange chromatography and high-performance gel permeation chromatography. Monosaccharide composition analysis showed that BRNP-1 and BRNP-2 were composed of glucosyl residues. Methylation and 1D- and 2D-NMR analyses revealed that both BRNP-1 and BRNP-2 contained a backbone chain that was composed of α-D-(1 → 4)-linked Glcp residues and side chains that were composed of terminally linked Glcp residues attached at the O-6 position of backbone-glycosyl residues. BRNP-1 and BRNP-2, however, differed in branch degree and molecular weight. Bioassay results showed that treatment with the higher dosage (400 μg/mL) of BRNP-1 and BRNP-2 stimulated the proliferation, NO release, and cytokine secretion (IL-6 and TNF-α) of RAW264.7 macrophages. These results suggested that BRNP-1 and BRNP-2 may enhance macrophage-mediated immune responses.
- Chen, Zhuo-Er,Wufuer, Reziyamu,Ji, Jin-Hu,Li, Jin-Fang,Cheng, Yu-Feng,Dong, Cai-Xia,Taoerdahong, Hailiqian
-
-
Read Online
- Transfer hydrogenation of cellulose-based oligomers over carbon-supported ruthenium catalyst in a fixed-bed reactor
-
Ru supported on activated carbon was found to be active for the transfer hydrogenation of cellulose oligomers, which were produced by the milling of acidulated microcrystalline cellulose. A C6 sugar alcohol yield of 85 % was obtained in less than 1 h reaction time in a batch reactor. Optimum reaction conditions for transfer hydrogenation were determined as 180 °C and a pH above 2.2 using glucose as a substrate. Use of deuterium as a marker established that direct transfer of hydride species from 2-propanol to glucose occurs through the dihydride mechanism. Formation of molecular hydrogen from 2-propanol dehydrogenation was found to be a side reaction, with little influence on the glucose hydrogenation step. Conversion of cellulose oligomers to hexitols was also achieved in a continuous flow fixed-bed reactor with 36.4 % yield at a liquid hourly space velocity of 4.7 h-1. The catalytic activity did not decrease even after 12 h of the onstream reaction. Fix that bed: The catalytic conversion of cellulose to sugar alcohols in high yield in a continuous flow fixed-bed reactor through hydrolytic transfer hydrogenation is described. Ru supported on activated carbon catalyses direct hydrogen transfer from 2-propanol to glucose without the involvement of hydrogen gas.
- Shrotri, Abhijit,Kobayashi, Hirokazu,Tanksale, Akshat,Fukuoka, Atsushi,Beltramini, Jorge
-
-
Read Online
- Excellent activity of ultrafine Co-B amorphous alloy catalyst in glucose hydrogenation
-
The ultrafine Co-B amorphous alloy, doped or undoped with Mo or W, were prepared by chemical reduction with borohydride. Its catalytic performance in liquid phase hydrogenation of glucose to sorbitol has been investigated, which revealed (i)the higher activity than that of crystalline Co and the Ni-based catalysts, and (ii)the promoting effect of Mo and W dopants on the activity.
- Li, Hui,Li, Hexing,Wang, Weijiang,Deng, Jing-Fa
-
-
Read Online
- Green catalysis by nanoparticulate catalysts developed for flow processing? Case study of glucose hydrogenation
-
Heterogeneous catalysis, flow chemistry, continuous processing, green solvents, catalyst immobilization and recycling are some of the most relevant, emerging key technologies to achieve green synthesis. However, a quantification of potential effects on a case to case level is required to provide a profound answer, whether they can lead to a superior process compared to the industrial standard. To do so, holistic environmental assessment approaches are very useful tools providing insights and decision support during the process development phase. Herein, novel heterogeneous nanoparticulate ruthenium catalysts immobilized on hyperbranched polystyrene (HPS) and nitrogen-doped carbon nanotubes (NCNT) were investigated with respect to their potential environmental impacts and improvements if utilized in an industrially highly relevant process, namely glucose hydrogenation to sorbitol. The results of a comparative Life Cycle Assessment of the alternative catalytic systems under consideration of RANEY nickel as benchmark catalyst revealed that in particular Ru nanoparticles on porous HPS beads processed under flow-chemistry conditions have the potential to improve the greenness of the overall synthesis, but the concentration of glucose in the reaction mixture is in fact the most influential parameter. This journal is
- Gericke, D?rthe,Ott, Denise,Matveeva, Valentina G.,Sulman, Esther,Aho, Atte,Murzin, Dmitry Yu.,Roggan, Stefan,Danilova, Lyudmila,Hessel, Volker,Loeb, Patrick,Kralisch, Dana
-
-
Read Online
- Catalytic conversion of glucose into sorbitol over niobium oxide supported Ru catalysts
-
Sorbitol is a sugar alcohol of great importance in cosmetic, food and pharmaceutical industry as well as the production of biopolymers. This work aimed at the synthesis of sorbitol from the hydrogenation of glucose using Ru/Nb2O5 catalysts in the amorphous and crystalline phases. The catalysts were synthesized from the wet impregnation method and characterized by N2 adsorption isotherms, TGA/DTG, EDXRF, XRD, TPR-H2, XPS and SEM. The catalytic tests presented results of high conversion rates of glucose reaching 85 % and 99 % of selectivity to sorbitol when using Nb2O5 in the crystalline form as support, and 53 % and 55 % in the conversion and selectivity, respectively, when the amorphous phase of Nb2O5 was used as support. The structural modification of the catalytic support positively favored the catalyst activity and sorbitol production, allowing the formation of nanometric particles of the active metal on the surface alongside the increase of the mesoporosity, thereby facilitating the transport of reagents.
- Silva, Jordan Gonzaga Andrade Batista,Santos, Ronaldo Costa,Rodríguez-Castellón, Enrique,Teixeira, Leonardo Sena Gomes,Pontes, Luiz Ant?nio Magalh?es
-
-
Read Online
- Glucose Hydrogenation on Promoted Raney-Nickel Catalysts
-
Glucose hydrogenation has been studied in a well stirred, high-pressure batch reactor on promoted Raney-nickel catalysts.Mo-, Cr-, and Fe-promoted catalysts were prepared by soda attack on Ni40-xAl60Mx alloys.Sn-promoted catalysts were obtained by controlled surface reaction of Sn(Bu)4 on the hydrogen-covered surface of a Raney-nickel obtained from a Ni2Al3 alloy.The loading of tin is stoichiometric and its distribution on the nickel surface is very homogeneous down to nanometer scale.For an optimum promoter concentration the catalysts are up to seven times more active than unpromoted ones.A good distribution of the promoter in the catalyst grain is required to obtain the best rate enhancement; in the case of molybdenum this is obtained by annealing the alloys.The promoters in a low-valent state on the nickel surface act as a Lewis adsorption sites for the oxygen atom of the carbonyl group which is then polarized and thus more easily hydrogenated via a nucleophilic attack on the carbon atom by hydride ions.The activities of Mo- and Cr-promoted catalysts decrease slightly after several recyclings in successive hydrogenation experiments.This is mostly due to surface poisoning by cracking products formed in side reactions.Fe- and Sn-promoted Raney-nickel catalysts deactivate very rapidly because Fe and Sn are leached away from the surface.Iron is washed to the liquid phase whereas tin remains in the Raney-nickel micropores.
- Gallezot, P.,Cerino, P. J.,Blanc, B.,Fleche, G.,Fuertes, P.
-
-
Read Online
- Efficient catalytic conversion of concentrated cellulose feeds to hexitols with heteropoly acids and Ru on carbon
-
A combination of heteropolyacids and Ru on carbon catalyzes the conversion of concentrated cellulose feeds into hexitols under H2 pressure. Quantitative conversion of ball-milled cellulose was observed with remarkable hexitol volume productivity.
- Geboers, Jan,Van De Vyver, Stijn,Carpentier, Kevin,De Blochouse, Kevin,Jacobs, Pierre,Sels, Bert
-
-
Read Online
- Hollow ni-p amorphous alloy nanospheres: An efficient catalyst for sugars hydrogenation to polyols
-
In this paper, hollow Ni ? P nanospheres (NSs) are prepared through Ni electroless plating on the Au-activated silica NSs externally covered by aminopropyl moieties, followed by removing the silica template with sodium hydroxide. With various characterizations, the resulting hollow Ni ? P NSs are identified to be amorphous alloy. During liquid-phase hydrogenation of sugars to sugar alcohols, the hollow Ni ? P amorphous alloy NSs delivered much superior catalytic performances to the commercial Raney Ni catalyst, showing a good potential in practical applications. Of particular interest is the unique hollow chamber structure of the hollow Ni ? P amorphous alloy NSs, which allows for improving catalytic activity and durability relative to those associated with the dense Ni ? P amorphous alloy NSs. This work demonstrated that such hollow Ni materials with nanoporous chamber structure displayed advantages such as easy experimental handling and high accessibility for the reactants in liquid-phase reaction, more Ni active sites, as well as the existence of more electron-enriched inner surface, which is essential to provide highly efficient catalysts for some reactions.
- Yong, Yang,Huajun, Gu,Qingxiao, Zhang,Fang, Zhang,Hui, Li
-
-
Read Online
- Control of selectivity, activity and durability of simple supported nickel catalysts for hydrolytic hydrogenation of cellulose
-
Efficient conversion of cellulose to sorbitol and mannitol by base metal catalysts is a challenge in green and sustainable chemistry, but typical supported base metal catalysts have not given good yields of hexitols or possessed durability. In this study, it has been demonstrated that a simple carbon-supported Ni catalyst affords up to 67% yield of hexitols in the conversion of cellulose, and that the catalyst is durable in the reuse experiments 7 times. In addition, the catalyst can be separated by a magnet thanks to a high content of Ni. Physicochemical analysis has indicated that the use of carbon supports has two benefits: no basicity and high water-tolerance. CeO2, ZrO2, γ-Al2O3 and TiO2 cause side-reactions due to basicity, and SiO2, γ-Al2O3 and CeO2 are less stable in hot water. Another important factor is high Ni loading as the increase of Ni content from 10 wt% to 70 wt% significantly improves the yield of hexitols and the durability of catalysts. Larger crystalline Ni particles are more resistant to sintering of Ni and surface coverage by Ni oxide species.
- Kobayashi, Hirokazu,Hosaka, Yuto,Hara, Kenji,Feng, Bo,Hirosaki, Yoshihiko,Fukuoka, Atsushi
-
-
Read Online
- Enhanced direct production of sorbitol by cellulose ball-milling
-
The catalytic conversion of lignocellulosic biomass to renewable and valuable chemicals has attracted global interest. Given the abundance of this renewable raw material and its reduced impact on the food chain, it is an attractive source for replacing fossil fuels and obtaining chemicals or fuels in the context of a sustainable economy. In this work, a catalyst (Ru/AC) was developed to perform, in a single step, hydrolysis and hydrogenation of cellulose to sorbitol. An activated carbon supported ruthenium catalyst was examined for the one-pot hydrolytic hydrogenation of cellulose and it has shown to be very active and selective for the conversion of cellulose into sorbitol. When microcrystalline cellulose was used, a conversion of 36% was reached after 5 hours of reaction, with a selectivity to sorbitol of 40%. On the other hand, ball-milled cellulose allowed attaining conversions close to 90%, with a selectivity to sorbitol of 50%. Moreover, if the catalyst was ball-milled together with cellulose, the selectivity to sorbitol could be further increased to almost 80%. The catalyst showed excellent stability after repeated use. In this work we combined hydrolysis and hydrogenation in one-pot (using heterogeneous catalysts instead of homogeneous), in the presence of a Ru/AC catalyst (without any support pre-treatment with acids) and pre-treated cellulose just by ball-milling (instead of using acids). For this reason, the results obtained in this work are one of the best values achieved when using supported metal catalysts to convert cellulose by an environmentally friendly process.
- Ribeiro, Lucília S.,órf?o, José J. M.,Pereira, Manuel Fernando R.
-
-
Read Online
- Glucose Hydrogenation on Ruthenium Catalysts in a Trickle-Bed Reactor
-
Glucose in 40 wt% aqueous solution was hydrogenated into sorbitol in a trickle-bed reactor over ruthenium catalysts supported on active charcoal pellets. The metal was loaded by cationic exchange or anionic adsorption. After reduction, ruthenium was under the form of 1-nm particles homogeneously distributed throughout the support. The reaction was conducted at 100°C under 8 MPa of hydrogen at 20 L h-1 flow rate. Conversion and selectivity to sorbitol were studied as a function of residence time. Whatever the mode of preparation, the catalysts give a total conversion of glucose with an initial specific activity of 1.1 mol h-1 g-1Ru. The selectivity to sorbitol was higher than 99.2% at 100% conversion; however, the liquid flow rate should be adjusted very accurately because any increase in the residence time results in a loss of selectivity due to epimerization of sorbitol into mannitol. The catalyst activity was stable over several weeks and no leaching of ruthenium was detected.
- Gallezot, Pierre,Nicolaus, Nathalie,Fleche, Guy,Fuertes, Patrick,Perrard, Alain
-
-
Read Online
- Highly effective aldose reductase mimetics: Microwave-assisted catalytic transfer hydrogenation of D-glucose to D-sorbitol with magnetically recoverable aminomethylphosphine-Ru(II) and Ni(II) complexes
-
The novel Ru(II) and Ni(II) complexes of aminomethylphosphine ligands supported on Fe3O4@SiO2 (core@shell) surface have been synthesized with Schlenk technique and characterized with Scanning Electron Microscopy (SEM), Energy-Dispersive X-Ray Spectroscopy (EDX), Transmission Electron Microscopy (TEM), X-Ray Diffraction Spectroscopy (XRD), Fourier-Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Spectroscopy (UV–Vis.), Thermogravimetric Analysis/Differential Thermal Analysis/ Differential Thermogravimetry (TG/DTA/DTG) and elemental analysis techniques. Besides, the synthesized complexes were tried as a catalyst in the transfer hydrogenation of D-glucose to D-sorbitol in isopropyl alcohol under microwave power at 150 °C for 1 h reaction time. K2CO3 was used as a base source in the catalysis. High-Performance Liquid Chromatography (HPLC) fitted Refractive Index Detector (RID) was used for the quantitative analyses of the catalytic tests. The complexes can be repeatedly usable and magnetically recoverable in the catalytic transfer hydrogenation of D-glucose to D-sorbitol. The complexes are also chemically selective and stable in the catalysis medium. In the recycling experiments, Ru(II) complexes were filtered and washed with isopropyl alcohol (IPA), dried and used again for the other catalytic cycles. Especially Ru(II) complexes showed the best catalytic properties, with over 91% selectivity on over 98% conversions under microwave power.
- Uru?, Serhan,Eskalen, Hasan,?aylar, Mahmut,Akbulut, Mehmet
-
-
Read Online
- One-pot conversion of cellulose to isosorbide using supported metal catalysts and ion-exchange resin
-
One-pot conversion of cellulose to isosorbide was investigated by supported metal catalysts and ion-exchange resin in water. The maximum isosorbide yield using supported platinum catalysts and Amberlyst 70 was less than 30%. The isosorbide yield drastically increased with supported ruthenium catalysts instead of supported platinum catalysts and it also increased with the loading of ruthenium on carbon support. One-pot conversion of cellulose to isosorbide by 4 wt.% ruthenium catalyst and Amberlyst 70 proceeded with isosorbide yield of 55.8%.
- Yamaguchi, Aritomo,Sato, Osamu,Mimura, Naoki,Shirai, Masayuki
-
-
Read Online
- Air-stable and reusable nickel phosphide nanoparticle catalyst for the highly selective hydrogenation ofd-glucose tod-sorbitol
-
The hydrogenation of carbohydrates to polyols is an industrially important process, but it requires air-unstable, non-noble metal catalysts with low activity and harsh reaction conditions. Herein, we report a hydrotalcite (HT)-supported nickel phosphide nanoparticle (nano-Ni2P/HT) that exhibits both air stability and high activity for the selective hydrogenation ofd-glucose tod-sorbitol in water. The nano-Ni2P/HT catalyst providesd-sorbitol in excellent yield with >99% selectivity under mild reaction conditions, and is the first non-noble metal catalyst that can operate under just 1 bar of H2or at ambient temperature. This high-performance nano-Ni2P/HT catalyst is significantly different from conventional Ni(0) and NiO nanoparticles and Raney catalysts, which result in almost no production ofd-sorbitol, demonstrating the unique catalysis of nano-Ni2P/HT. Furthermore, nano-Ni2P/HT shows the highest activity among those reported for non-noble metal catalysts. The nano-Ni2P/HT catalyst can also be reused without sacrificing its high activity and selectivity. Additionally, the successful transformation of a concentratedd-glucose solution (50 wt%) tod-sorbitol has been achieved. This is the first example of an air-stable, highly active, and reusable non-noble metal catalyst that can replace conventional catalysts used ford-sorbitol production, thus providing a cheap, green, and sustainable route for this process.
- Yamaguchi, Sho,Fujita, Shu,Nakajima, Kiyotaka,Yamazoe, Seiji,Yamasaki, Jun,Mizugaki, Tomoo,Mitsudome, Takato
-
-
Read Online
- Ce promoted Cu/γ-Al2O3 catalysts for the enhanced selectivity of 1,2-propanediol from catalytic hydrogenolysis of glucose
-
Ce promoted Cu/γ-Al2O3 catalysts were prepared with varying amounts of Cu (x = 0–10 wt%) and Ce (y = 0–15 wt%). The prepared catalysts were characterized and tested for the conversion of aqueous glucose (5 wt%) to 1,2-propanediol in a batch reactor. 10%Ce-8%Cu/γ-Al2O3 showed the complete conversion of glucose with 62.7% selectivity of 1,2-propanediol and total glycols (1,2-propanediol, ethylene glycol & 1,2-butanediol) of 81% at milder reaction conditions. Cu facilitated the hydrogenation activity and Ce loading optimize the acid/base sites of Cu/γ-Al2O3 which obtain high selectivity of 1, 2-propanediol. Catalyst reusability is reported.
- Balachandran Kirali, Arun Arunima,Marimuthu, Banu,Sreekantan, Sreejith
-
-
- Efficient Synthesis of Sugar Alcohols over a Synergistic and Sustainable Catalyst
-
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
-
p. 2467 - 2476
(2021/07/16)
-
- Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses
-
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
-
supporting information
p. 721 - 725
(2020/10/19)
-
- Product Control and Insight into Conversion of C6 Aldose Toward C2, C4 and C6 Alditols in One-Pot Retro-Aldol Condensation and Hydrogenation Processes
-
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
-
p. 560 - 566
(2021/06/25)
-
- Conversion of glucose to levulinic acid and upgradation to γ-valerolactone on Ru/TiO2catalysts
-
Combining glucose dehydration and the subsequent hydrogenation in one pot is a preferable approach for process development as such a method allows in situ generation of the reactive intermediate to undergo further reaction without extra energy-intensive separation. Herein, phosphotungstic acid and various types of titania (anatase, rutile, P25) supported Ru-based catalysts were considered as the dehydration and hydrogenation catalysts, respectively. Modulating the different reactant media (N2, H2), various products were obtained with GBL-H2O as the solvent. A considerable yield (42%) of levulinic acid (LA) and γ-valerolactone (GVL) (40%) were obtained in nitrogen and subsequent hydrogen. Ru/TiO2 (rutile) was the favorable hydrogenation catalyst among the three types of Ru/TiO2. Meanwhile, a certain amount of sorbitol (36%) was obtained in pure hydrogen. The hydrogenation of glucose is more likely to occur than the glucose dehydration. The physicochemical properties of the catalysts were characterized by XRD, BET, TPR, STEM and in situ CO/FT-IR, and the results show that well-dispersed Ru particles are located on the rutile crystallites, which facilitated the hydrogenation of LA. A strong metal support interaction (SMSI) was responsible for the various microstructure properties and the different hydrogenation reactivity. This work allows a better understanding of the reaction paths of glucose conversion.
- Ding, Guoqiang,Liu, Yubo,She, Haohao,Yang, Yong,Zhao, Guoping,Zhu, Yulei
-
p. 14406 - 14413
(2021/08/23)
-
- Elucidating the effect of solid base on the hydrogenation of C5 and C6 sugars over Pt–Sn bimetallic catalyst at room temperature
-
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.
-
-
- HYDROGENATION OF L-SORBOSE
-
The invention relates to a process for L-Iditol by hydrogenating L-Sorbose. Further, the invention also relates to a use of a transition metal complex as hydrogenation catalyst for L-Sorbose. The invention relates to a process for the preparation of L-Iditol comprising at least one reaction step, in which a composition comprising L-Sorbose and hydrogen is reacted in the presence of a transition metal catalyst complex in a homogeneous solution, wherein the transition metal catalyst complex comprises at least one chiral ligand containing at least one phosphorus atom, which is capable of coordinating to the transition metal, and wherein the transition metal is selected from metals of groups 8, 9 and 10 of the periodic table of the elements according to IUPAC. The invention further relates to a use of a transition metal complex as defined above and below as hydrogenation catalyst for compositions comprising L-Iditol or mixtures thereof.
- -
-
Page/Page column 31-32
(2021/10/22)
-
- A Water/Toluene Biphasic Medium Improves Yields and Deuterium Incorporation into Alcohols in the Transfer Hydrogenation of Aldehydes
-
Deuterium labeling is an interesting process that leads to compounds of use in different fields. We describe the transfer hydrogenation of aldehydes and the selective C1 deuteration of the obtained alcohols in D2O, as the only deuterium source. Different aromatic, alkylic and α,β-unsaturated aldehydes were reduced in the presence of [RuCl(p-cymene)(dmbpy)]BF4, (dmbpy=4,4′-dimethyl-2,2′-bipyridine) as the pre-catalyst and HCO2Na/HCO2H as the hydrogen source. Moreover, furfural and glucose, were selectively reduced to the valuable alcohols, furfuryl alcohol and sorbitol. The processes were carried out in neat water or in a biphasic water/toluene system. The biphasic system allowed easy recycling, higher yields, and higher selective D incorporation (using D2O/toluene). The deuteration took place due to an efficient effective M–H/D+ exchange from D2O that allows the inversion of polarity of D+ (umpolung). DFT calculations that explain the catalytic behavior in water are also included.
- Ruiz-Casta?eda, Margarita,Santos, Lucía,Manzano, Blanca R.,Espino, Gustavo,Jalón, Félix A.
-
p. 1358 - 1372
(2021/03/16)
-
- L-Xylo-3-hexulose, a new rare sugar produced by the action of acetic acid bacteria on galactitol, an exception to Bertrand Hudson's rule
-
Background: In acetic acid bacteria such as Gluconobacter oxydans or Gluconobacter cerinus, pyrroloquinoline quinone (PQQ) in the periplasm serves as the redox cofactor for several membrane-bound dehydrogenases that oxidize polyhydric alcohols to rare sugars, which can be used as a healthy alternative for traditional sugars and sweeteners. These oxidation reactions obey the generally accepted Bertrand Hudson's rule, in which only the polyhydric alcohols that possess cis D-erythro hydroxyl groups can be oxidized to 2-ketoses using PQQ as a cofactor, while the polyhydric alcohols excluding cis D-erythro hydroxyl groups ruled out oxidation by PQQ-dependent membrane-bound dehydrogenases. Methods: Membrane fractions of G. oxydans were prepared and used as a cell-free catalyst to oxidize galactitol, with or without PQQ as a cofactor. Results: In this study, we reported an interesting oxidation reaction that the polyhydric alcohols galactitol (dulcitol), which do not possess cis D-erythro hydroxyl groups, can be oxidized by PQQ-dependent membrane-bound dehydrogenase(s) of acetic acid bacteria at the C-3 and C-5 hydroxyl groups to produce rare sugars L-xylo-3-hexulose and D-tagatose. Conclusions: This reaction may represent an exception to Bertrand Hudson's rule. General significance: Bertrand Hudson's rule is a well-known theory in polyhydric alcohols oxidation by PQQ-dependent membrane-bound dehydrogenase in acetic acid bacteria. In this study, galactitol oxidation by a PQQ-dependent membrane-bound dehydrogenase represents an exception to the Bertrand Hudson's rule. Further identification of the associated enzymes and deciphering the explicit enzymatic mechanism will prove this theory.
- Xu, Yirong,Chi, Ping,Lv, Jiyang,Bilal, Muhammad,Cheng, Hairong
-
-
- A novel low-molecular-mass pumpkin polysaccharide: Structural characterization, antioxidant activity, and hypoglycemic potential
-
The novel natural low-molecular-mass polysaccharide (SLWPP-3) from pumpkin (Cucurbia moschata) was separated from the waste supernatant after macromolecular polysaccharide production and purified using a DEAE cellulose-52 column and gel-filtration chromatography. Chemical and instrumental studies revealed that SLWPP-3 with a molecular mass of 3.5 kDa was composed of rhamnose, glucose, arabinose, galactose and uronic acid with a weight ratio of 1: 1: 4: 6: 15, and primarily contained →3,6)-β-D-Galp-(1→, →4)-α-GalpA-(1→(OMe), →4)-α-GalpA-(1→, →2,4)-α-D-Rhap-(1→, →3)-β-D-Galp-(1→, →4)-α-D-Glcp, and →4)-β-D-Galp residues in the backbone. The branch chain passes were connected to the main chain through the O-4 atom of glucose and O-3 atom of arabinose. Physiologically, the ability of SLWPP-3 to inhibit carbohydrate-digesting enzymes and DPPH and ABTS radicals, as well as protect pancreatic β cells from oxidative damage by decreasing MDA levels and increasing SOD activities, was confirmed. The findings elucidated the structural types of pumpkin polysaccharides and revealed a potential adjuvant natural product with hypoglycemic effects.
- Huang, Linlin,Li, Fei,Li, Quanhong,Liang, Li,Wei, Yunlu,Yu, Guoyong
-
-
- PROCESS FOR PREPARING ALKYLENE GLYCOL MIXTURE FROM A CARBOHYDRATE SOURCE WITH DECREASED SELECTIVITY FOR POLYOL SIDE PRODUCTS
-
The invention relates to a process for preparing a mixture of alkylene glycols (e.g. ethylene glycol and/or propylene glycol) from a carbohydrate source by catalytic conversion with hydrogen. More specifically, the catalytic hydrogenolysis process of the invention has a decreased selectivity for larger polyols like sorbitol and erythritol, which larger polyols are obtained generally as a side product in catalytic hydrogenolysis, when viewed in comparison to the selectivity for small alkylene glycols (like ethylene glycol and propylene glycol). This is achieved by ensuring the carbohydrate feed is rich in sucrose.
- -
-
Page/Page column 7-9
(2021/08/27)
-
- Enhanced one-pot selective conversion of cellulose to ethylene glycol over NaZSM-5 supported metal catalysts
-
The mesopores interconnected with microporous NaZSM-5 was synthesised by sol-gel method. Reactions involving cellulose using different bimetallic and trimetallic combinations of nickel, aluminium, and tungsten metals supported on NaZSM-5 have been carried out. Different weight percentages (wt%) of Al, Ni, and W were loaded onto the NaZSM-5 support via a wet impregnation method. The prepared catalysts were characterized using PXRD, FE-SEM, HR-TEM, BET, and XPS studies to investigate the presence of mesopores, the textural properties, the metal loading, and the active oxidation states. The catalytic activities of the xAl-yNi-zW/NaZSM-5 (where x, y, and z are the wt% values of Al, Ni, and W, respectively) supported catalysts were studied during the one-pot conversion of cellulose into ethylene glycol at 220 °C and with a pressure of 70 bar H2 (at the reaction temperature) in water (as a solvent). The 5%Al-8%Ni-25%W/NaZSM-5 catalyst exhibited the highest cellulose conversion of 100%, with an ethylene glycol yield as high as 89% (C mol%) under moderate reaction conditions being reported for the first time. Al3+ in the catalyst hydrolyzed cellulose, and W5+ species acted as acid centres that facilitated the retro-aldol condensation reaction and eventually led to an increased EG yield in the presence of Ni. The catalyst was moderately stable after four consecutive runs for 6 h at 220 °C and at a H2 reaction pressure of 70 bar, though a 12 h reaction resulted in the highest EG yield. The high yields under moderate reaction conditions promise an energy-efficient and economically feasible process.
- Arunima Kirali, Arun,Marimuthu, Banu,Sreekantan, Sreejith
-
supporting information
p. 19244 - 19254
(2021/11/09)
-
- The main factors affecting the catalytic properties of Ru/Cs-HPA systems in one-pot hydrolysis-hydrogenation of cellulose to sorbitol
-
One-pot conversion of mechanically activated cellulose to sorbitol was investigated over bifunctional catalysts based on Ru (0.6, 1 and 3 wt.%) and cesium salts of heteropoly acids (HPA) Cs2.1H0.9PW12O40 and Cs3HSiW12O40 (Cs-PW and Cs-SiW, respectively). The maximal yield of sorbitol equal to 59 % and selectivity 94 % were achieved over the 1%Ru/Cs3HSiW12O40 catalyst. Physicochemical and catalytic data showed that the rate-determining step, i.e. the hydrolysis of cellulose, depended on the surface acidity of catalysts, whereas Ru content in catalyst affected both the hydrolysis and the hydrogenation steps. The kinetic parameters for one-pot conversion of cellulose were determined by mathematical modeling approach and were successfully used for the prediction of the yields of sorbitol and mannitol.
- Gerasimov, Evgeniy Yu.,Gromov, Nikolay V.,Kozhevnikov, Ivan V.,Medvedeva, Tatiana B.,Panchenko, Valentina N.,Parmon, Valentin N.,Said-Aizpuru, Olivier,Taran, Oxana P.,Timofeeva, Maria N.
-
-
- Direct conversion of cellulose into isosorbide over Ni doped NbOPO4catalysts in water
-
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
-
supporting information
p. 10292 - 10299
(2020/07/14)
-
- Hydrogenation of crude and purified d-glucosone generated by enzymatic oxidation of d-glucose
-
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.
-
p. 30476 - 30480
(2020/09/11)
-
- Method for preparing sorbitol
-
The invention discloses a method for preparing sorbitol, which utilizes transition metal catalysis and uses isopropanol as hydrogen source to synthesize sorbitol. The reaction not only uses inexpensive and environmentally friendly isopropanol as the hydrogen source and a solvent, but also has the advantages of high yield, environmental protection, and the like, and therefore the reaction has important development significance.
- -
-
Paragraph 0023; 0024; 0025; 0026; 0027
(2019/03/17)
-
- Synergistic effect between copper and different metal oxides in the selective hydrogenolysis of glucose
-
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
-
p. 3733 - 3742
(2019/03/05)
-
- Harnessing the reactivity of poly(methylhydrosiloxane) for the reduction and cyclization of biomass to high-value products
-
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.
-
p. 2662 - 2669
(2019/06/13)
-
- CONTINUOUS OR SEMI-CONTINUOUS PROCESS FOR THE PREPARATION OF ETHYLENE GLYCOL AND CATALYST SYSTEM FOR USE THEREIN
-
A continuous or semi-continuous process for the preparation of ethylene glycol from a carbohydrate source including: reacting, in a reactor, at a temperature in the range from equal to or more than 170°C to equal to or less than 270°C, at least a portion of a carbohydrate source in the presence of hydrogen, a solvent, and a catalyst system, to yield ethylene glycol; wherein the catalyst system includes: a homogeneous catalyst, which homogeneous catalyst contains tungsten; and a heterogeneous catalyst, which heterogeneous catalyst contains one or more transition metals from groups 8, 9 and 10 of the Periodic Table of the Elements supported on a carrier; and wherein continuously or periodically additional heterogeneous catalyst is added to the reactor. Further described is a catalyst system that can be used in such a process.
- -
-
Paragraph 0107-0126
(2019/10/04)
-
- Selective Conversion of Cellulose to Hydroxyacetone and 1-Hydroxy-2-Butanone with Sn–Ni Bimetallic Catalysts
-
The high-value-added chemicals hydroxyacetone (HA) and 1-hydroxy-2-butanone (HB) were produced from agricultural waste over a Ni3Sn4-SnOx catalyst. The Sn–Ni intermetallic compound and SnOx acted as the active sites for HA and HB production by selectively cleaving the target C?C and C?O bonds. Approximately 70 % of the total HA and HB yield was obtained by selective hydrogenolysis of cellulose. This strategy expands the application of cellulose towards renewable production of high-value C3 and C4 keto-alcohols from cellulosic biomass.
- Wang, Haiyong,Zhu, Changhui,Liu, Qiying,Tan, Jin,Wang, Chenguang,Liang, Zheng,Ma, Longlong
-
p. 2154 - 2160
(2019/03/21)
-
- Effect of Cu addition to carbon-supported Ru catalysts on hydrogenation of alginic acid into sugar alcohols
-
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
-
-
- Highly efficient catalytic conversion of cellulose into acetol over Ni-Sn supported on nanosilica and the mechanism study
-
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
-
p. 5647 - 5656
(2019/11/05)
-
- Integration of Enzymatic and Heterogeneous Catalysis for One-Pot Production of Fructose from Glucose
-
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
-
p. 1157 - 1162
(2018/03/21)
-
- PROCESS FOR THE PRODUCTION OF GLYCOLS
-
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.
- -
-
Page/Page column 13-15
(2018/03/28)
-
- Effective conversion of cellobiose and glucose to sorbitol using non-noble bimetallic NiCo/HZSM-5 catalyst
-
The tandem hydrolysis and hydrogenation of saccharides into sorbitol is an especially attractive reaction in the conversion of biomass. Here, an economical and efficient bimetallic catalyst for the transformation of glucose and cellobiose into sorbitol is reported. Non-precious metal based catalysts such as NiCo, Ni, and Co, were prepared via modified impregnation method, and NiCo/HZSM-5 showed superior performance for the synthesis of sorbitol (86.9% from cellobiose, 98.6% from D-glucose). Various characterizations, such as Brunner-Emmet-Teler (BET), X-ray diffraction (XRD), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), confirmed that NiCo alloy formed and highly dispersed in NiCo/HZSM-5 catalyst. The high performance of fabricated catalyst would be attributed to the formation of nickel-cobalt alloy over HZSM-5 zeolite surface. High temperature and H2 pressure were favorable for the tandem hydrolysis and hydrogenation reaction. Besides, the reaction pathway was also proposed based on the kinetics study. Cellobitol was detected as the intermediate in the reaction mixture. Furthermore, in the catalytic stability study, it was found that active metal species of NiCo/HZSM-5 were stable. The deactivation of catalyst would be due to the covering of acidic sites over NiCo/HZSM-5.
- Zada, Bakht,Yan, Long,Fu, Yao
-
p. 1167 - 1174
(2018/08/17)
-
- Method for preparing sugar alcohol and coproducing white carbon black
-
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.
- -
-
Paragraph 0053-0061; 0071-0079; 0098-0100; 0101-0103
(2018/06/04)
-
- Method for preparation of mannitol from fructose using butanol as solvent
-
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.
- -
-
Page/Page column 6-10
(2018/12/11)
-
- Method for preparation of mannitol from fructose using butanol as solvent
-
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
- -
-
Page/Page column 7-10
(2019/01/09)
-
- Electrocatalytic Biosynthesis using a Bucky Paper Functionalized by [Cp*Rh(bpy)Cl]+ and a Renewable Enzymatic Layer
-
A bioelectrode for electroenzymatic synthesis was prepared, combining a layer for NADH regeneration and a renewable layer for enzymatic substrate reduction. The covalent immobilization of a rhodium complex mediator ([Cp*Rh(bpy)Cl]+) on the surface of a bucky paper electrode was achieved by following an original protocol in two steps. A bipyridine ligand was first grafted on the electrode by electro-reduction of bipyridyl diazonium cations generated from 4-amino-2,2′-bipyridine, and the complex was then formed by reaction with [RhCp*Cl2]2. A turnover frequency of 1.3 s?1 was estimated for the electrocatalytic regeneration of NADH by this immobilized complex, with a Faraday efficiency of 83 %. The bucky paper electrode was then overcoated by a bio-doped porous layer made of glassy fibers with immobilized D-sorbitol dehydrogenase. This assembly allowed for the efficient separation of the enzyme and the rhodium catalyst, which is a prerequisite for effective bioelectrocatalysis with such bioelectrochemical system, while allowing effective mass transport of NAD+/NADH cofactor from one layer to the other. Thereby, it was possible to reuse the same mediator-functionalized bucky paper with three different enzyme layers. The bioelectrode was applied to the electroenzymatic reduction of D-fructose to D-sorbitol. A turnover frequency of 0.19 s?1 for the rhodium complex was observed in the presence of 3 mM D-fructose and a total turnover number higher than 12000 was estimated.
- Zhang, Lin,Etienne, Mathieu,Vilà, Neus,Le, Thi Xuan Huong,Kohring, Gert-Wieland,Walcarius, Alain
-
p. 4067 - 4073
(2018/08/11)
-
- Oleanane-type glycosides from the roots of Weigela florida “rumba” and evaluation of their antibody recognition
-
Three triterpene glycosides were isolated from the roots of Weigela florida “rumba” (Bunge) A. DC.: two previously undescribed 3-O-β-D-xylopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→4)]-β-D-xylopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-
- Champy-Tixier, Anne-Sophie,Mitaine-Offer, Anne-Claire,Real Fernández, Feliciana,Miyamoto, Tomofumi,Tanaka, Chiaki,Papini, Anna-Maria,Lacaille-Dubois, Marie-Aleth
-
p. 198 - 203
(2018/05/29)
-
- Production of ethylene glycol from direct catalytic conversion of cellulose over a binary catalyst of metal-loaded modified SBA-15 and phosphotungstic acid
-
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
-
p. 24857 - 24865
(2018/07/29)
-
- Coupling glucose dehydrogenation with co2 hydrogenation by hydrogen transfer in aqueous media at room temperature
-
Conversion of CO2 into value-added chemicals and fuels provides a direct solution to reduce excessive CO2 in the atmosphere. Herein, a novel catalytic reaction system is presented by coupling the dehydrogenation of glucose with the hydrogenation of a CO2-derived salt, ammonium carbonate, in an ethanol–water mixture. For the first time, the hydrogenation of CO2 to formate by glucose has been achieved under ambient conditions. Under the optimal reaction conditions, the highest yield of formate reached approximately 46 %. We find that the apparent pH value in the ethanol–water mixture plays a central role in determining the performance of the hydrogen-transfer reaction. Based on the13 C NMR and ESI–MS results, a possible pathway of the coupled glucose dehydrogenation and CO2 hydrogenation reactions was proposed.
- Ding, Guodong,Su, Ji,Zhang, Cheng,Tang, Kan,Yang, Lisha,Lin, Hongfei
-
-
- WATER-SOLUBLE SOLID OR SEMI-SOLID DISPERSION OF PARTICLES
-
Disclosed are solid or semisolid compositions the including finely divided particles and a water-soluble matrix that dissolves and disperses the particles when in contact with water. Also disclosed are kits for reducing and/or inhibiting odor formation on garment. The kit include one or more containers, wherein at least one of the one or more container includes solid or semisolid compositions the including finely divided particles and a water-soluble matrix that dissolves and disperses the particles when in contact with water. An edible silver delivery system including the compositions is disclosed as are methods of delivering silver to a subject in need thereof.
- -
-
-
- Role of the Strong Lewis Base Sites on Glucose Hydrogenolysis
-
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
-
p. 3845 - 3853
(2018/07/31)
-
- Hydrothermally Stable Ruthenium–Zirconium–Tungsten Catalyst for Cellulose Hydrogenolysis to Polyols
-
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
-
p. 612 - 618
(2017/12/28)
-
- A using a supported metal catalyst method for preparing alcohols (by machine translation)
-
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)
- -
-
Paragraph 0056-0061
(2017/09/01)
-
- NOVEL LACTIC ACID BACTERIUM
-
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.
- -
-
-
- PROCESS FOR PRODUCTION OF D-SORBITOL
-
The present invention relates to a new process for the production of D-sorbitol.
- -
-
Page/Page column 20
(2017/02/09)
-
- AN ECO-FRIENDLY PROCESS FOR HYDROGENATION OR/AND HYDRODEOXYGENATION OF ORGANIC COMPOUND USING HYDROUS RUTHENIUM OXIDE CATALYST
-
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).
- -
-
Page/Page column 13; 20
(2017/08/01)
-
