- 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
-
-
- METHOD FOR PRODUCING ALCOHOL
-
The present invention provides a method for selectively producing an alcohol by efficiently hydrogenating a lactone. The present invention is a method for producing an alcohol, the method including hydrogenating a substrate lactone represented by Formula (1), in the presence of a catalyst described below, to produce an alcohol that is represented by Formula (2). In the formulae, R represents a divalent hydrocarbon group which may have a hydroxyl group. The catalyst comprises: metal species including M1 and M2; and a support supporting the metal species, and wherein M1 is rhodium, platinum, ruthenium, iridium, or palladium; M2 is tin, vanadium, molybdenum, tungsten, or rhenium; and the support is hydroxyapatite, fluorapatite, hydrotalcite, or ZrO2.
- -
-
Paragraph 0104-0106
(2022/02/05)
-
- Promotional effect of indium on Cu/SiO2catalysts for the hydrogenation of dimethyl oxalate to ethylene glycol
-
The synthesis of ethylene glycol (EG) through hydrogenation of syngas-derived dimethyl oxalate (DMO) has been a promising method because syngas can be obtained from plentiful resources such as coal, natural gas, biomass,etc.In this work, we fabricated several indium-promoted Cu/SiO2catalysts by a one-pot hydrolysis precipitation (HP) method for the DMO-to-EG reaction. The textural and physiochemical properties of the catalysts were revealed using multiple characterization methods. The intimate contact of Cu and In enhances the reduction of indium oxide and the formation of CuIn alloy. The introduction of indium also markedly improves the copper dispersion and formation of Cu0active sites, which improve the activation of H2. The plentiful interface of Cu+-CuIn alloy prompts the conversion of the carbonyl group adsorbed on the Cu+sites with the dissociated hydrogen on the vicinal CuIn alloy, which is confirmed by the higher TOF (Cu+) and the lower apparent activation energy (Ea) on the Cu1In/SiO2catalyst. Both CuIn alloy and Cu0species have a synergistic effect with Cu+, endowing the Cu1In/SiO2catalyst with a higher EG yield (96%) in comparison with the Cu/SiO2catalyst without doping.
- Huang, Huijiang,Kong, Lingxin,Ma, Xinbin,Wang, Hui,Wang, Shengping,Wang, Xiaofei,Xu, Yuxi,Zhao, Yujun
-
p. 6854 - 6865
(2021/10/25)
-
- Catalytic Diastereo- and Enantioconvergent Synthesis of Vicinal Diamines from Diols through Borrowing Hydrogen
-
We present herein an unprecedented diastereoconvergent synthesis of vicinal diamines from diols through an economical, redox-neutral process. Under cooperative ruthenium and Lewis acid catalysis, readily available anilines and 1,2-diols (as a mixture of diastereomers) couple to forge two C?N bonds in an efficient and diastereoselective fashion. By identifying an effective chiral iridium/phosphoric acid co-catalyzed procedure, the first enantioconvergent double amination of racemic 1,2-diols has also been achieved, resulting in a practical access to highly valuable enantioenriched vicinal diamines.
- Feng, Wei,Gao, Taotao,Lau, Kai Kiat,Lin, Yamei,Pan, Hui-Jie,Yang, Binmiao,Zhao, Yu
-
supporting information
p. 18599 - 18604
(2021/08/09)
-
- Well-defined Cp*Co(III)-catalyzed Hydrogenation of Carbonates and Polycarbonates
-
We herein report the catalytic hydrogenation of carbonates and polycarbonates into their corresponding diols/alcohols using well-defined, air-stable, high-valent cobalt complexes. Several novel Cp*Co(III) complexes bearing N,O-chelation were isolated for the first time and structurally characterized by various spectroscopic techniques including single crystal X-ray crystallography. These novel Co(III) complexes have shown excellent catalytic activity to produce value added diols/alcohols from carbonate and polycarbonates through hydrogenation using molecular hydrogen as sole reductant or iPrOH as transfer hydrogenation source. To demonstrate the developed methodology's practical applicability, we have recycled the bisphenol A monomer from compact disc (CD) through hydrogenation under the established reaction conditions using phosphine-free, earth-abundant, air- and moisture-stable high-valent cobalt catalysts.
- Dahiya, Pardeep,Gangwar, Manoj Kumar,Sundararaju, Basker
-
p. 934 - 939
(2020/12/15)
-
- The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Br?nsted acid catalysts
-
The acid–base neutralization reaction of commercially available disodium 2,6-naphthalenedisulfonate (NDS, 2 equivalents) and the tetrahydrochloride salt of tetrakis(4-aminophenyl)methane (TAPM, 1 equivalent) in water gave a novel three-dimensional charge-assisted hydrogen-bonded framework (CAHOF, F-1). The framework F-1 was characterized by X-ray diffraction, TGA, elemental analysis, and 1H NMR spectroscopy. The framework was supported by hydrogen bonds between the sulfonate anions and the ammonium cations of NDS and protonated TAPM moieties, respectively. The CAHOF material functioned as a new type of catalytically active Br?nsted acid in a series of reactions, including the ring opening of epoxides by water and alcohols. A Diels–Alder reaction between cyclopentadiene and methyl vinyl ketone was also catalyzed by F-1 in heptane. Depending on the polarity of the solvent mixture, the CAHOF F-1 could function as a purely heterogeneous catalyst or partly dissociate, providing some dissolved F-1 as the real catalyst. In all cases, the catalyst could easily be recovered and recycled.
- Belokon, Yuri N.,Dmitrienko, Artem O.,Gak, Alexander S.,Gerasimov, Igor S.,Kuznetsova, Svetlana A.,Larionov, Vladimir A.,Li, Han,Medvedev, Michael G.,Nelyubina, Yulia V.,North, Michael,Saghyan, Ashot S.,Smol'yakov, Alexander F.,Zhereb, Vladimir P.
-
supporting information
p. 1124 - 1134
(2020/07/10)
-
- Method for preparing 1, 3-butanediol
-
The invention provides a method for preparing 1, 3-butanediol. The method comprises the following steps: (1) carrying out condensation cyclization reaction on butadiene, water and an aldehyde ketone compound according to a certain material ratio in the presence of hydrogen peroxide and a catalyst A to obtain a reaction solution containing an intermediate I; and (2) mixing the reaction solution containing the intermediate I with a certain amount of water, and carrying out hydrolysis reaction in the presence of a catalyst B to obtain 1, 3-butanediol and a corresponding aldehyde ketone compound.Compared with the existing production method, the method has the advantages of accessible reaction raw materials, high reaction conversion rate, high selectivity and the like, and is suitable for industrial production.
- -
-
Paragraph 0061; 0064-0066; 0076; 0077
(2020/11/22)
-
- Olefin reaction in the catalyst and the olefin production
-
PROBLEM TO BE SOLVED: To provide a catalyst for obtaining an olefin in high selectivity with a vicinal diol as a raw material.SOLUTION: A catalyst for olefination reaction for use in a reaction to produce an olefin by a reaction of a polyol, having two adjacent carbon atoms each having a hydroxy group, with hydrogen comprises: a carrier; at least one oxide selected from the group consisting of oxides of the group 6 elements and oxides of the group 7 elements supported on the carrier; and at least one metal selected from the group consisting of silver, iridium, and gold supported on the carrier.SELECTED DRAWING: None
- -
-
Paragraph 0145-0146; 0149
(2020/10/31)
-
- PNN tridentate ligand, ruthenium complex, and preparation method and application of ruthenium complex
-
The invention discloses a PNN tridentate ligand, a ruthenium complex, and a preparation method and an application of the ruthenium complex. The structure of the ruthenium complex is represented by formula I, and the ruthenium complex has good catalytic activity in a reaction of converting cyclic carbonate into methanol and a reaction of hydrogenating and degrading polyester and polycarbonate. In addition, the PNN tridentate ligand and the ruthenium complex of the PNN tridentate ligand are good in stability, and the synthesis process is simple.
- -
-
Paragraph 0159-0192
(2020/06/04)
-
- Magnesium-catalyzed hydroboration of organic carbonates, carbon dioxide and esters
-
A low-valent magnesium(i) complex [(XylNacnac)Mg]2 was employed as a highly efficient precatalyst for the hydroboration of a variety of cyclic and linear organic carbonates, polycarbonates, CO2 and esters with HBpin under mild conditions. The resultant boronates can be used for the preparation of the corresponding value-added diols, triols or alcohols through hydrolysis.
- Cao, Xu,Lu, Kai,Ma, Mengtao,Wang, Weifan,Xue, Fei,Yao, Weiwei
-
supporting information
p. 2776 - 2780
(2020/03/13)
-
- Transfer hydrogenation of cyclic carbonates and polycarbonate to methanol and diols by iron pincer catalysts
-
Herein, we report the first example on the use of an earth-abundant metal complex as the catalyst for the transfer hydrogenation of cyclic carbonates to methanol and diols. The advantage of this method is the use of isopropanol as the hydrogen source, thus avoiding the handling of flammable hydrogen under high pressure. The reaction offers an indirect route for the reduction of CO2 to methanol. In addition, poly(propylene carbonate) was converted to methanol and propylene glycol. This methodology can be considered as an attractive opportunity for the chemical recycling of polycarbonates.
- Liu, Xin,De Vries, Johannes G.,Werner, Thomas
-
supporting information
p. 5248 - 5255
(2019/10/11)
-
- Asymmetric ring opening of racemic epoxides for enantioselective synthesis of (S)-β-amino alcohols by a cofactor self-sufficient cascade biocatalysis system
-
A novel one-pot epoxide hydrolase/alcohol dehydrogenase/transaminase cascade process for the asymmetric ring opening of racemic epoxides to enantiopure β-amino alcohols is reported. The product (S)-β-amino alcohols were obtained in 97-99% ee and 79-99% conversion from readily available racemic epoxides.
- Zhang, Jian-Dong,Yang, Xiao-Xiao,Jia, Qiao,Zhao, Jian-Wei,Gao, Li-Li,Gao, When-Chao,Chang, Hong-Hong,Wei, Wen-Long,Xu, Jian-He
-
-
- Topotactic Conversion of Alkali-Treated Intergrown Germanosilicate CIT-13 into Single-Crystalline ECNU-21 Zeolite as Shape-Selective Catalyst for Ethylene Oxide Hydration
-
The conversion of the alkali-treated intergrowth germanosilicate CIT-13 into the single-crystalline high-silica ECNU-21 (named after East China Normal University) zeolite, with a novel topology and a highly crystalline zeolite framework, has been realized through a creative top-down strategy involving a mild alkaline-induced multistep process consisting of structural degradation and reconstruction. Instead of acid treatment, hydrolysis in aqueous ammonia solution not only readily cleaved the chemically weak Ge(Si)?O?Ge bonds located within the interlayer double four ring (D4R) units of CIT-13, but also cleaved the metastable Si?O?Si bonds therein. This led to extensive removal of the D4R units, and also generated silanol groups on adjacent silica-rich layers, which then condensed to form a novel daughter structure upon calcination. Individual oxygen bridges in the reassembled ECNU-21 replaced the germanium-rich D4R units in CIT-13, thereby eliminating the original intergrowth phenomenon along the b axis. With an ordered crystalline structure of 10-ring (R) channels as well as suitable germanium-related Lewis acid sites, ECNU-21 serves as a stable solid Lewis acid catalyst for the shape-selective hydration of ethylene oxide (EO) to ethylene glycol (EG) at greatly reduced H2O/EO ratios and reaction temperature in comparison with the noncatalytic industrial process.
- Liu, Xue,Mao, Wenting,Jiang, Jingang,Lu, Xinqing,Peng, Mingming,Xu, Hao,Han, Lu,Che, Shun-ai,Wu, Peng
-
p. 4520 - 4529
(2019/03/07)
-
- Bifunctional organocatalysts for the conversion of CO2, epoxides and aryl amines to 3-aryl-2-oxazolidinones
-
A route to synthesize 3-aryl-2-oxazolidinones is developed, which is achieved through a three component reaction between CO2, aryl amines, and epoxides with a binary organocatalytic system composed of organocatalysts and DBU (1,8-diazabicyclo[5.4.0]undec-7-ene). The method allows wide scopes of epoxide and aryl amine substrates with various functional groups under mild reaction conditions. The control experiments indicate that a cyclic carbonate is formed via cycloaddition of epoxides with CO2, which further reacts with the β-amino alcohol originating from epoxides and aryl amines, resulting in the formation of 3-aryl-2-oxazolidinones finally.
- Xie, Ya-Fei,Guo, Cheng,Shi, Lei,Peng, Bang-Hua,Liu, Ning
-
supporting information
p. 3497 - 3506
(2019/04/14)
-
- 1. 2 - O-alcohol synthetic method of the compound (by machine translation)
-
The invention relates to a 1, 2 - O-alcohol synthetic method of the compound. The synthetic method comprises the following steps: (1) in order to at the end of the olefin as raw materials, potassium persulfate compound salt as the oxidizing agent, inorganic salt as catalyst, water and ketone organic solvent as a reaction solvent, for 30 - 100 °C reaction; (2) reaction after the end of the, 0 - 40 °C adding inorganic alkali, the pH for the reaction system 10 - 14; (3) for 30 - 100 °C continue to reaction, after the end of the reaction, separation and purification, be 1, 2 - O-alcohol compound. The method for synthesis of mild reaction system, the raw material is cheap, the oxidizing agent is environment-friendly, good reaction selectivity, high conversion rate. (by machine translation)
- -
-
Paragraph 0030; 0031
(2019/03/17)
-
- CATALYST FOR ONE CARBON-REDUCTION REACTION, AND METHOD FOR PRODUCING ONE CARBON-REDUCTION COMPOUND USING THE SAME
-
PROBLEM TO BE SOLVED: To provide a method for producing selectively a one carbon-reduction compound, using a compound having a primary hydroxy group, a carboxyl group, or an alkoxycarbonyl group, or a lactone compound, as a substrate. SOLUTION: A method of obtaining a one carbon-reduction compound includes the reaction of a compound as a substrate represented by formula (1-1) or (1-2) or (1-3) with hydrogen in the presence of a catalyst in which a metal selected from Ru, Rh, Pd, Ir, and Pt is supported on a support selected from CeO2, hydroxyapatite, ZrO2, TiO2, hydrotalcite, SiO2, MgO, and Al2O3 (R1-R3 independently represent H, a substituted/unsubstituted monovalent hydrocarbon group, or a monovalent group in which two or more hydrocarbon groups are bound together through a linking group; R1-R3 may form a ring with adjacent carbon; L is a substituted/unsubstituted divalent hydrocarbon group or the like; and n is an integer of 0 or greater). SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
- -
-
Paragraph 0060; 0070; 0071
(2018/07/28)
-
- Enzyme-mediated enantioselective hydrolysis of 1,2-diol monotosylate derivatives bearing an unsaturated substituent
-
We have succeeded in the easy preparation of optically active 1,2-diol monotosylates bearing an unsaturated substituent via enzymatic hydrolysis. Lipase PS quickly catalyzes the hydrolyses of 2-acetoxybut-3-enyl tosylate, which has a double bond, and 2-acetoxybut-3-ynyl tosylate, which has a triple bond, with excellent enantioselectivity to afford the corresponding optically active compounds. The reaction is also applicable to acetates with a longer chain, which has a double bond at the terminus. To demonstrate the applicability of this method, enantiomerically pure (R)-massoialactone, a natural coconut flavor, has been synthesized from racemic 2-acetoxypent-4-enyl tosylate in several steps. Furthermore, the enzyme can recognize the stereochemistry of olefins, and the (Z)-alkenyl structure is more suitable for the enantioselective hydrolysis than the (E)-isomer.
- Matsumoto,Oohana,Hashimoto,Usuda,Shimoda,Ohshima,Suzuki,Togawa
-
supporting information
p. 3981 - 3988
(2018/06/15)
-
- Hydrogenolysis of sorbitol into valuable C3-C2 alcohols at low H2 pressure promoted by the heterogeneous Pd/Fe3O4 catalyst
-
The hydrogenolysis of sorbitol and various C5-C3 polyols (xylitol; erythritol; 1,2- 1,4- and 2,3-butandiol; 1,2-propandiol; glycerol) have been investigated at low molecular hydrogen pressure (5 bar) by using Pd/Fe3O4, as heterogeneous catalyst and water as the reaction medium. Catalytic experiments show that the carbon chain of polyols is initially shortened through dehydrogenation/decarbonylation and dehydrogenation/retro-aldol mechanisms followed by a series of cascade reactions that include dehydrogenation/decarbonylation and dehydration/hydrogenation processes. At 240 °C, sorbitol is fully converted into lower alcohols with ethanol being the main reaction product in liquid phase.
- Gumina, Bianca,Mauriello, Francesco,Pietropaolo, Rosario,Galvagno, Signorino,Espro, Claudia
-
p. 152 - 160
(2018/02/17)
-
- The hydrolysis of epoxides catalyzed by inorganic ammonium salts in water: Kinetic evidence for hydrogen bond catalysis
-
Naturally-occurring inorganic ammonium ions have been recently reported as efficient catalysts for some organic reactions in water, which contributes to the understanding of the chemistry in some natural environments (soils, seawater, atmospheric aerosols, .) and biological systems, and is also potentially interesting for green chemistry as many of their salts are cheap and non-toxic. In this work, the effect of NH4+ ions on the hydrolysis of small epoxides in water was studied kinetically. The presence of NH4+ increased the hydrolysis rate by a factor of 6 to 25 compared to pure water and these catalytic effects were shown not to result from other ions, counter-ions or from acid or base catalysis, general or specific. The small amounts of amino alcohols produced in the reactions were identified as the actual catalysts by obtaining a strong acceleration of the reactions when adding these compounds directly to the epoxides in water. Replacing the amino alcohols by other strong hydrogen-bond donors, such as trifluoroethanol (TFE) or hexafluoroisopropanol (HFIP) gave the same results, demonstrating that the kinetics of these reactions was driven by hydrogen-bond catalysis. Because of the presence of many hydrogen-bond donors in natural environments (for instance amines and hydroxy-containing compounds), hydrogen-bond catalysis is likely to contribute to many reaction rates in these environments.
- Nozière,Fache,Maxut,Fenet,Baudouin,Fine,Ferronato
-
p. 1583 - 1590
(2018/02/06)
-
- Ordered Mesoporous NiCeAl Containing Catalysts for Hydrogenolysis of Sorbitol to Glycols
-
Cellulose-derived sorbitol is emerging as a feasible and renewable feedstock for the production of value-added chemicals. Highly active and stable catalyst is essential for sorbitol hydrogenolysis. Ordered mesoporous M–xNiyCeAl catalysts with different loadings of nickel and cerium species were successfully synthesized via one-pot evaporation-induced self-assembly strategy (EISA) and their catalytic performance were tested in the hydrogenolysis of sorbitol. The physical chemical properties for the catalysts were characterized by XRD, N2 physisorption, H2-TPR, H2 impulse chemisorption, ICP and TEM techniques. The results showed that the ordered mesopores with uniform pore sizes can be obtained and the Ni nanoparticles around 6 nm in size were homogeneously dispersed in the mesopore channels. A little amount of cerium species introduced would be beneficial to their textural properties resulting in higher Ni dispersion, metal area and smaller size of Ni nanoparticles. The M–10Ni2CeAl catalyst with Ni and Ce loading of 10.9 and 6.3 wt % shows better catalytic performance than other catalysts, and the yield of 1,2-PG and EG can reach 56.9% at 493 K and 6 MPa pressure for 8 h after repeating reactions for 12 times without obvious deterioration of physical and chemical properties. Ordered mesoporous M–NiCeAl catalysts are active and stable in sorbitol hydrogenolysis.
- Zhou, Zhiwei,Zhang, Jiaqi,Qin, Juan,Li, Dong,Wu, Wenliang
-
p. 456 - 465
(2018/03/21)
-
- 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)
-
- Mechanistic study on -C-O- and -C-C- hydrogenolysis over Cu catalysts: Identification of reaction pathways and key intermediates
-
Important petro-based polyol compounds with a longer carbon chain, such as oligohydroxy hexanes (e.g. 1,2- and 1,6-hexanediol or 1,2,6-hexanetriol), require at least three to four synthesis steps. Replacing this complex chemistry by a one-pot reaction via -C-O- bond cleavage from sugars would be a significant breakthrough for the use of renewable feedstocks. Cu is known for its dehydroxylation (deoxygenation) properties, yielding the desired products from sugars. In this joint research between academic and industrial chemistry, we have identified so far unknown intermediate products and present the first mechanism that explains the selective cleavage of OH-groups over copper. Strong interactions between polyols, unsaturated species and the copper surface are observed. Stable five-membered rings are formed with Cu via two vicinal OH-groups of the polyol reactant that makes these OH-groups inert to -C-O- bond cleavage. Adjacent free OH-groups in close proximity to the catalyst are dehydroxylated (deoxygenated). We further show that degradation of polyols not only occurs via commonly cited retro-aldol reactions. The formation of acid intermediates with subsequent decarboxylation is validated as a new pathway for -C-C- bond cleavage to short-chain polyols and CO2. The proposed mechanisms for -C-O- and -C-C- bond cleavage elucidate why hydrogenolysis reactions require high hydrogen pressure (up to 200 bar) to suppress the degradation of sugars and obtain high yields of deoxy C6 products. With this knowledge, the improvement of a standard commercial Cu-RANEY catalyst under optimized reaction conditions was shown. In contrast to alumina-supported Cu, the Cu-Al alloy in a RANEY-type catalyst shows selective -C-O- bond cleavage properties while maintaining the C6 carbon chain. These new insights into the transformation of sugars to value added commodities show the potential for new approaches in future biorefinery concepts.
- Kühne, Benjamin,Vogel, Herbert,Meusinger, Reinhard,Kunz, Sebastian,Kunz, Markwart
-
p. 755 - 767
(2018/02/14)
-
- Catalytic Hydrogenation of Cyclic Carbonates using Manganese Complexes
-
Catalytic hydrogenation of cyclic carbonates to diols and methanol was achieved using a molecular catalyst based on earth-abundant manganese. The complex [Mn(CO)2(Br)[HN(C2H4PiPr2)2] 1 comprising commercially available MACHO ligand is an effective pre-catalyst operating under relatively mild conditions (T=120 °C, p(H2)=30–60 bar). Upon activation with NaOtBu, the formation of coordinatively unsaturated complex [Mn(CO)2[N(C2H4PiPr2)2)] 5 was spectroscopically verified, which confirmed a kinetically competent intermediate. With the pre-activated complex, turnover numbers up to 620 and 400 were achieved for the formation of the diol and methanol, respectively. Stoichiometric reactions under catalytically relevant conditions provide insight into the stepwise reduction form the CO2 level in carbonates to methanol as final product.
- Kaithal, Akash,H?lscher, Markus,Leitner, Walter
-
supporting information
p. 13449 - 13453
(2018/09/25)
-
- Hydrogenation of CO2-Derived Carbonates and Polycarbonates to Methanol and Diols by Metal–Ligand Cooperative Manganese Catalysis
-
The first base-metal-catalysed hydrogenation of CO2-derived carbonates to alcohols is presented. The reaction proceeds under mild conditions in the presence of a well-defined manganese complex with a loading as low as 0.25 mol %. The non-precious-metal homogenous catalytic system provides an indirect route for the conversion of CO2 into methanol with the co-production of value-added (vicinal) diols in yields of up to 99 %. Experimental and computational studies indicate a metal–ligand cooperative catalysis mechanism.
- Zubar, Viktoriia,Lebedev, Yury,Azofra, Luis Miguel,Cavallo, Luigi,El-Sepelgy, Osama,Rueping, Magnus
-
supporting information
p. 13439 - 13443
(2018/09/21)
-
- Method for synthesizing o-glycol compounds by virtue of bifunctional characteristic catalyst
-
The invention belongs to the technical field of organic chemical synthesis and particularly relates to a method for synthesizing o-glycol compounds by virtue of a bifunctional characteristic catalyst.The o-glycol compounds are prepared from olefin and an oxidizing agent through reaction under the effect of the bifunctional characteristic catalyst, wherein the bifunctional characteristic catalystcontains the following components in percentage by mass: 25%-75% of a titanium silicalite molecular sieve, 20%-70% of nano-silicon dioxide and 5%-10% of heteropolyacid. The method provided by the invention has the beneficial effects that a process for synthesizing o-glycol by virtue of a traditional two-step method is simplified; the catalyst can still remain good catalytic performance under a long-period operation condition in the method, the raw material conversion rate is high, and the yields of the o-glycol compounds are high; and the olefin raw material conversion rate is 80.2%-94.6%, andthe selectivity of o-glycol generated through reaction is 85.7%-96.3%.
- -
-
Paragraph 0034-0035; 0036-0037; 0039-0045
(2018/04/26)
-
- Method for synthesizing vicinal diol compound by virtue of one-step process
-
The invention belongs to the technical field of organic chemical synthesis, and in particular relates to a method for synthesizing a vicinal diol compound by virtue of a one-step process. The vicinaldiol compound is obtained by carrying out reaction on olefin and an oxidizing agent in presence of a bifunctional catalyst, wherein the bifunctional catalyst comprises 25-75% of titanium silicalite molecular sieves, 20-70% of nano alumina and 3-8% of boric oxide in percentage by mass with the titanium silicalite molecular sieves, nano alumina and boric oxide as the benchmarks. The method for synthesizing the vicinal diol compound has the advantages that the traditional two-step vicinal diol synthesis technology is simplified; in the synthetic method, a catalyst still maintains good catalytic performance under long-period operation condition, raw material conversion rate is high, and yield of the vicinal diol compound is high; and olefin raw material conversion rate is 80.2-94.6%, and vicinal diol reaction generation selectivity is 85.7-96.3%.
- -
-
Paragraph 0032-0041
(2018/04/26)
-
- Method for hydrogenation synthesis of ethylene glycol from oxalate
-
The invention relates to a method for catalytic hydrogenation synthesis of ethylene glycol from oxalate. The method mainly solves the problem that the existing catalytic reaction process for oxalate hydrogenation synthesis of ethylene glycol has low selectivity and a short catalyst life. Metal copper or copper oxide is used as an active component in the catalyst, hydrophilic silica or modified hydrophilic silica is used as a carrier and an appropriate metal oxide assistant is used. The catalyst has high reaction performances and reaction stability.
- -
-
Paragraph 0060-0064; 0066-0067; 0070-0071; 0074-0076
(2018/04/02)
-
- Method for preparing vicinal diol compound through ring-opening reaction
-
The present invention discloses a method for preparing a vicinal diol compound through a ring-opening reaction. The method takes a hydrocarbons epoxide as a raw material and takes an anion exchange resin as a catalyst. The vicinal diol compound is prepared by using a fixed bed continuous hydrolysis reaction technology. The anion exchange resin is a halogen-substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used many times, the raw material conversion rate is high, and the yield of the vicinal diol compound is high.
- -
-
Paragraph 0015; 0031; 0033; 0036
(2017/03/28)
-
- Method for synthesizing ortho-diol compound by using macroporous anion exchange resin as catalyst
-
The invention discloses a method for synthesizing an ortho-diol compound by using macroporous anion exchange resin as a catalyst. According to the method, hydrocarbon epoxide is used as a raw material, the anion exchange resin is used as the catalyst, and a fixed bed continuous hydrolysis reaction technology is adopted for preparing the ortho-diol compound; the anion exchange resin is halogen ortho-substituted macroporous polystyrene-divinyl benzene quaternary phosphonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used repeatedly, the conversion rate of the raw material is high, and the yield of the ortho-diol compound is high.
- -
-
Paragraph 0024; 0025; 0026; 0028; 0029; 0030-0035
(2017/05/27)
-
- Method of using anion exchange resin as catalyst to synthesize vicinal diol compound
-
The invention discloses a method of using anion exchange resin as a catalyst to synthesize a vicinal diol compound. The method includes: using hydrocarbon epoxide as a raw material and the anion exchange resin as the catalyst; adopting a fixed bed continuous hydrolysis reaction process to obtain the vicinal diol compound, wherein the anion exchange resin is halogen substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The method is simple, the catalyst can be utilized repeatedly, the raw material is high in conversion rate, and the vicinal diol compound is high in yield.
- -
-
Paragraph 0027; 0029; 0030; 0036
(2017/07/06)
-
- Method for synthesizing vicinal diol compound which takes hydrocarbon epoxide as raw material
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The present invention discloses a method for preparing a vicinal diol compound which takes a hydrocarbon epoxide as a raw material. The method takes the hydrocarbon epoxide as the raw material and takes an anion exchange resin as a catalyst. The vicinal diol compound is prepared by using a fixed bed continuous hydrolysis reaction technology. The anion exchange resin is a halogen-substituted macroporous polystyrene-divinyl benzene quaternary ammonium salt type anion exchange resin. The synthesis method is simple, the catalyst can be used many times, the raw material conversion rate is high, and the yield of the vicinal diol compound is high.
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Paragraph 0027-0028; 0032; 0037
(2017/08/03)
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- Synthetic method for o-glycol compounds
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The invention discloses a synthetic method for o-glycol compounds. The method prepares the o-glycol compounds by using a fixed-bed continuous hydrolysis reaction process with hydrocarbon epoxides as raw materials and anion exchange resin as a catalyst, wherein the anion exchange resin is halogen-p-substituted macroporous polystyrene-divinyl benzene quaternary phosphonium salt anion exchange resin. The synthetic method is simple; the catalyst can be repeatedly used a plurality of times; the conversion rate of the raw materials is high; and the yield of the o-glycol compounds is high.
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Paragraph 0026-0027; 0029-0036
(2017/08/28)
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- Cooperative Activation of Cobalt–Salen Complexes for Epoxide Hydration Promoted on Flexible Porous Organic Frameworks
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Developing solid catalysts with multiple active sites working cooperatively is desirable for efficient chemical transformations. However, most solid catalysts are rigid and impede the cooperation between their spatially isolated active sites. Two flexible porous organic frameworks (POFs) with integrated Co(salen) as active sites have been successfully synthesized for mimicking the cooperative modes of enzymes. The POFs exhibit second-order rate dependence on Co(salen) concentration in the network and afford much higher TOF (3300 versus 2670 h?1) than the homogeneous counterpart in the hydration of propylene epoxide. POFs with a flexible network thus not only facilitate but also enhance the cooperation of nearby Co(salen). Moreover, POFs could catalyze oversized substrates, have a wide substrate scope, and exhibit high stability.
- Zhong, Mingmei,Li, He,Chen, Jian,Tao, Lin,Li, Can,Yang, Qihua
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supporting information
p. 11504 - 11508
(2017/08/30)
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- Selective C?O Hydrogenolysis of Erythritol over Supported Rh-ReOx Catalysts in the Aqueous Phase
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Bimetallic Rh-ReOx (Re/Rh molar ratio 0.4–0.5) catalysts supported on TiO2 and ZrO2 were prepared by the successive impregnation of dried and calcined unreduced supported Rh catalysts. Their catalytic performances were evaluated in the hydrogenolysis of erythritol to butanetriols (BTO) and butanediols (BDO) in aqueous solution at 150–240 °C under 30–120 bar H2. The activity depended on the nature of the support, and the highest selectivity to BTO and BDO at 80 % conversion was 37 and 29 %, respectively, in the presence of 3.7 wt %Rh-3.5 wt %ReOx/ZrO2 at 200 °C under 120 bar. The characterization of the catalysts by CO chemisorption, TEM with energy-dispersive X-ray spectroscopy, thermogravimetric analysis with MS, and X-ray photoelectron spectroscopy suggests a different distribution and reducibility of Re species over the supported Rh nanoparticles, which depends on the support.
- Said, Achraf,Da Silva Perez, Denilson,Perret, Noémie,Pinel, Catherine,Besson, Michèle
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p. 2768 - 2783
(2017/07/28)
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- Iridium Clusters Encapsulated in Carbon Nanospheres as Nanocatalysts for Methylation of (Bio)Alcohols
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C?H methylation is an attractive chemical transformation for C?C bonds construction in organic chemistry, yet efficient methylation of readily available (bio)alcohols in water using methanol as sustainable C1 feedstock is limited. Herein, iridium nanocatalysts encapsulated in yolk–shell-structured mesoporous carbon nanospheres (Ir@YSMCNs) were synthesized for this transformation. Monodispersed Ir clusters (ca. 1.0 nm) were encapsulated in situ and spatially isolated within YSMCNs by a silica-assisted sol–gel emulsion strategy. A selection of (bio)alcohols (19 examples) was selectively methylated in aqueous phase with good-to-high yields over the developed Ir@YSMCNs. The improved catalytic efficiencies in terms of activity and selectivity together with the good stability and recyclability were contributable to the ultrasmall Ir clusters with oxidation chemical state as a consequence of the confinement effect of YSMCNs with interconnected nanostructures.
- Liu, Qiang,Xu, Guoqiang,Wang, Zhendong,Liu, Xiaoran,Wang, Xicheng,Dong, Linlin,Mu, Xindong,Liu, Huizhou
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p. 4748 - 4755
(2017/12/15)
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- Synergistic Effect of a Boron-Doped Carbon-Nanotube-Supported Cu Catalyst for Selective Hydrogenation of Dimethyl Oxalate to Ethanol
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Heteroatom doping is a promising approach to improve the properties of carbon materials for customized applications. Herein, a series of Cu catalysts supported on boron-doped carbon nanotubes (Cu/xB-CNTs) were prepared for the hydrogenation of dimethyl oxalate (DMO) to ethanol. The structure and chemical properties of boron-doped catalysts were characterized by XRD, TEM, N2O pulse adsorption, CO chemisorption, H2 temperature-programmed reduction, and NH3 temperature-programmed desorption, which revealed that doping boron into CNT supports improved the Cu dispersion, strengthened the interaction of Cu species with the CNT support, introduced more surface acid sites, and increased the surface area of Cu0 and especially Cu+ sites. Consequently, the catalytic activity and stability of the catalysts were greatly enhanced by boron doping. 100 % DMO conversion and 78.1 % ethanol selectivity could be achieved over the Cu/1B-CNTs catalyst, the ethanol selectivity of which was almost 1.7 times higher than that of the catalyst without boron doping. These results suggest that doping CNTs with boron is an efficient approach to improve the catalytic performance of CNT-based catalysts for hydrogenation of DMO. The boron-doped CNT-based catalyst with improved ethanol selectivity and catalytic stability will be helpful in the development of efficient Cu catalysts supported on non-silica materials for selective hydrogenation of DMO to ethanol.
- Ai, Peipei,Tan, Minghui,Yamane, Noriyuki,Liu, Guoguo,Fan, Ronggang,Yang, Guohui,Yoneyama, Yoshiharu,Yang, Ruiqin,Tsubaki, Noritatsu
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supporting information
p. 8252 - 8261
(2017/06/23)
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- SYNTHESIS OF R-GLUCOSIDES, SUGAR ALCOHOLS, REDUCED SUGAR ALCOHOLS, AND FURAN DERIVATIVES OF REDUCED SUGAR ALCOHOLS
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Disclosed herein are methods for synthesizing 1,2,5,6-hexanetetrol (HTO), 1,6 hexanediol (HDO) and other reduced polyols from C5 and C6 sugar alcohols or R glycosides. The methods include contacting the sugar alcohol or R-glycoside with a copper catalyst, most desirably a Raney copper catalyst with hydrogen for a time, temperature and pressure sufficient to form reduced polyols having 2 to 3 fewer hydoxy groups than the starting material. When the starting compound is a C6 sugar alcohol such as sorbitol or R-glycoside of a C6 sugar such as methyl glucoside, the predominant product is HTO. The same catalyst can be used to further reduce the HTO to HDO.
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Paragraph 0070
(2017/05/31)
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- Metal nanoparticles supported on WO3 nanosheets for highly selective hydrogenolysis of cellulose to ethylene glycol
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Although the conversion of cellulose to polyols is currently well-developed, the production of the considerably valuable ethylene glycol (EG) is still challenging. Reactions have long relied on the design of suitable catalysts to obtain a high selectivity and yield of EG. Herein, using well-shaped rectangular tungsten trioxide nanosheets as the substrate, we investigated the catalytic performances of various metal supported catalysts for the convertion of cellulose to EG. Results show that Ru/WO3 is more favorable for EG production, with the highest EG yield of 76.3% over the 1% Ru/WO3 nanosheet catalyst. Our characterizations and activity tests suggest that the embedding of Ru nanoparticles onto the WO3 nanosheets produces more W5+ active sites under the same reduction conditions (NaBH4 or H2), which act as Lewis base sites to promote the glucose retro-aldol condensation reaction. Moreover, the Ru/WO3 catalyst holds a portion of Ru in the form of amorphous RuOxδ+ phases, which could further increase the H+ released into an aqueous solution for cellulose hydrogenolysis. A possible catalytic mechanism for this hydrogenolysis process is accordingly proposed.
- Li, Naixu,Zheng, Yu,Wei, Lingfei,Teng, Hongcheng,Zhou, Jiancheng
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p. 682 - 691
(2017/02/26)
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- Effect of tungsten surface density of WO3-ZrO2 on its catalytic performance in hydrogenolysis of cellulose to ethylene glycol
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One-pot hydrogenolysis of cellulose to ethylene glycol (EG) was carried out on WO3-based catalysts combined with Ru/C. To probe the active catalytic site for breaking the C-C bond of cellulose, a series of WO3-ZrO2 (WZr) catalysts were synthesized and systematically characterized with XRD, Raman, UV-Vis, H2-TPR, DRIFS and XPS techniques and N2 physisorption experiment. It was found that the WO3 crystallites became more easily reduced to W5+-OH species with increasing crystallite size or tungsten surface density of the WZr catalyst owing to the decrease of their absorption edge energy (AEE) originating from weakening their interaction with ZrO2 support. This, as a result, gave higher EG yield at higher tungsten surface density. The structure-activity relationship of the WZr catalyst reveals that the active catalytic site for cleaving the C2-C3 bond of the glucose molecule is the W5+-OH species.
- Chai, Jiachun,Zhu, Shanhui,Cen, Youliang,Guo, Jing,Wang, Jianguo,Fan, Weibin
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p. 8567 - 8574
(2017/02/10)
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- Synthesis, Characterization and Catalytic Application of Pyridine-Bridged N-Heterocyclic Carbene–Ruthenium Complexes in the Hydrogenation of Carbonates
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A series of bulky pyridine-bridged NHC–Ru complexes have been rationally designed and synthesized; these exhibited very high catalytic activity in the hydrogenation of cyclic and linear carbonates under mild reaction conditions. In the presence of catalytic amounts of a weak base, a broad range of substrates with different ring size and steric bulk were well tolerated, providing methanol and the corresponding diols in excellent yields with a catalyst loading as low as 0.5 mol %.
- Chen, Jiangbo,Zhu, Haibo,Chen, Jinjin,Le, Zhang-Gao,Tu, Tao
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supporting information
p. 2809 - 2812
(2017/10/23)
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- Reactivity of the CH-bonds of 2-butanol in liquid-phase oxidation
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The kinetics of product accumulation is studied in the azodiisobutyronitrile-initiated oxidation of 2-butanol. The relative reactivity for all types of the CH-bonds of 2-butanol is determined for reactions with peroxyl radicals at 60°C. It is established that the hydroxyl functional group of 2-butanol activates the CHbond in position 2 (α) and deactivates CH-bonds in positions 1, 3 (β), and 4 (γ), compared to the corresponding CH-bonds of saturated hydrocarbons.
- Puchkov,Nepomnyashchikh, Yu. V.
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p. 2337 - 2343
(2017/11/09)
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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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- Reactive distillation method and device for efficient hydrolysis of glycol acetal/ketone product
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The invention relates to a reactive distillation method and device for efficient hydrolysis of a glycol acetal/ketone product. A hydrolysis reaction distillation column comprises a distillation section, a stripping section and a reactive distillation section, the glycol acetal/ketone product and water are mixed and enter the column from the upper part of the reactive distillation section or from the upper part and the lower part of the reactive distillation section respectively, hydrolyzate aldehyde/ketone is extracted from the top of the column, a mixed stream of glycol and water extracted from a column kettle enters a glycol refining column, and a high-purity glycol product is obtained. The method and the device have the advantages that two unit operations including a hydrolysis reaction and rectification separation are organically coupled, equipment investment is saved, the following operating cost is also reduced, besides, a high conversion rate and high purity of the glycol product can be obtained, and basic guarantee is provided for an economical, efficient and energy-saving acetal/ketone reaction distillation separation process of a glycol mixture.
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Paragraph 0036; 0037
(2016/11/28)
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- Method and catalyst for hydrogenating oxalate to produce methyl glycolate
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The invention relates to a method and a catalyst for hydrogenating oxalate to produce methyl glycolate. The problems of low selectivity of glycolate in hydrogenation products and high catalyst cost existing in previous technologies are mainly solved. In the invention, metal copper or an oxide thereof is adopted as an active component, a silica-containing composite oxide, such as SBA-15 and a molecular sieve, is adopted as a carrier, and an appropriate metal or an oxide assistant is added. The structure characteristic of the silicon-containing composite oxide molecular sieve is adopted to highly disperse the active component copper or the oxide thereof, so the reaction conversion rate and the methyl glycolate selectivity are improved; adoption of a precious metal assistant is avoided, so the catalyst cost is reduced; and a high oxalate conversion rate and a high methyl glycolate selectivity are simultaneously realized.
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Paragraph 0020; 0021; 0028; 0029
(2017/03/14)
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- Epoxidation of alkenes catalyzed by some molybdenum(0) and molybdenum(IV) complexes
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Catalytic epoxidations of styrene, cyclohexene, 1-octene, and 3,3-dimethyl-1-butene have been explored utilizing a variety of molybdenum(0) and molybdenum(IV) complexes as precatalysts and tert-butylhydroperoxide (TBHP) as oxidant. The catalytic activities of the complexes MoCl4(CH3CN)2, Mo(CO)3(PTA)3 (PTA = 1,3,5-triaza-7-phosphaadamantane), Mo(CO)3(Mes), and a molybdenum(IV) calix[4]arene salt, [Et3NH][Mo{tBuC4}Cl(CH3CN)] have been investigated. The progress of reactions was monitored with reference to an internal standard by means of 1H NMR spectroscopy. Most of the complexes were found to be effective precatalysts with low catalyst loadings, giving rise to good to excellent conversion of alkenes and yield of the epoxides with the formation of minimal amount of corresponding diol and other side products. The catalytic reactions were found to be most efficient between 100 and 110 °C in minimal solvent or without added solvent.
- Acharya, Sitaram,Hanna, Tracy A.
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p. 113 - 123
(2016/02/18)
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- Lewis Acid Catalysis Confined in Zeolite Cages as a Strategy for Sustainable Heterogeneous Hydration of Epoxides
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We report a heterogeneous catalysis strategy to the sustainable hydration of epoxides by designing robust Lewis acid catalysts confined in zeolite cages as natural shape-selective nanoreactors. In the case of ethylene oxide hydration, Sn-H-SSZ-13 zeolite exhibits remarkable catalytic performance, with an ethylene oxide conversion above 99% and a monoethylene glycol selectivity above 99%, at approaching stoichiometric water/ethylene oxide ratios and near-ambient reaction temperatures. It is revealed by theoretical studies that partially hydroxylated Sn species are the preferred Lewis acid sites for the hydration of ethylene oxide. The concept of Lewis acid catalysis confined in zeolite cages may be applied in the future in the chemical industry to develop energy-saving and environmentally benign processes.
- Dai, Weili,Wang, Chuanming,Tang, Bo,Wu, Guangjun,Guan, Naijia,Xie, Zaiku,Hunger, Michael,Li, Landong
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p. 2955 - 2964
(2016/07/06)
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- Catalytic conversion of cellulose for efficient ethylene glycol production and insights into the reaction pathways
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As promising and environmentally friendly catalysts, tungsten-containing heteropoly acids combined with supported noble metals were used for one-pot hydrothermal conversion of cellulose into polyols in the presence of pressurized hydrogen. The microcrystalline cellulose was completely converted over a mixed catalyst consisting of a low concentration of phosphotungstic acid (PTA) (0.03 wt%) and Ru/activated carbon (Ru/AC) via an one-pot hydrothermal reaction, with an ethylene glycol (EG) yield of up to 53.1% under optimal conditions. The catalytic activity of the mixed catalyst gradually decreased with increasing reaction runs, which could be mainly ascribed to the aggregation of Ru/AC particles, and to the coverage of the active sites of Ru due to the deposition of organic materials. Cellobiose was used as a model feedstock for a comparative study on the reaction pathways of the conversion of cellulose, and the results revealed that catalytic conversion of cellobiose consisted of at least three important parallel reactions under the present hydrothermal conditions, which were also most likely involved during the catalytic conversion of cellulose for EG production. Effective control of these reactions would be helpful to further maximize the EG yield during the catalytic conversion of cellulose.
- Zhang, Kai,Wu, Shubin,Yang, He,Yin, Huimin,Li, Gang
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p. 77499 - 77506
(2018/06/22)
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- WOx modified Cu/Al2O3 as a high-performance catalyst for the hydrogenolysis of glucose to 1,2-propanediol
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Glucose is one of the most important platform molecules of biomass in nature. The selective hydrogenolysis of glucose to 1,2-PDO is still a challenge. However, The hydrogenolysis of fructose has higher activity and selectivity to 1,2-PDO. Therefore, A series of Cu-WOx/Al2O3 catalysts with high activity for glucose isomerization to fructose and fructose hydrogenolysis to 1,2-PDO were designed for glucose hydrogenolysis to 1,2-PDO. The W surface density was controlled as low as 0.8 W/nm2. The low W surface density could make the WOx species present as isolated WO4 structure, which could only provide more Lewis acid sites. As a result, the isolated WO4 species could form a complex with glucose and then promote the isomerization of glucose to fructose. The isolated WO4 species also have coverage, dispersion, and electronic effects on copper sites, resulting more stable copper sites and proper amount of hydrogenation sites on Cu-WOx/Al2O3 surface. The correlations between the ratio of Lewis acid amount to Cu surface area and the selectivity of 1,2-PDO suggest that the hydrogenolysis of glucose to 1,2-PDO follows the bifunctional reaction route which contains the reactions on Lewis acid and metal sites. Furthermore, the highest 1,2-PDO selectivity of 55.4% was obtained on Cu-WOx(0.8)/Al2O3.
- Liu, Chengwei,Zhang, Chenghua,Zhu, Yulei,Li, Yongwang,Hao, Shunli,Sun, Sikai,Liu, Kangkai,Xu, Jian
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p. 116 - 127
(2016/01/26)
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- CONTINUOUS PROCESS FOR PREPARING ETHYLENE GLYCOL FROM A CARBOHYDRATE SOURCE
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Ethylene glycol is prepared from a carbohydrate source by reaction of the carbohydrate source with hydrogen in a continuous process, wherein hydrogen, the carbohydrate source and a liquid diluent are continuously fed into a continuous stirred tank reactor wherein a catalyst system is present, which catalyst system comprises a tungsten compound and at least one hydrogenolysis metal selected from the groups 8, 9 or 10 of the Periodic Table of the Elements, to achieve the reaction between the carbohydrate source and hydrogen to ethylene glycol; wherein continuously a product mixture comprising ethylene glycol and diluent is removed from the continuous stirred tank reactor; and wherein continuously or periodically further at least a tungsten compound is added to the continuous stirred tank reactor (CSTR).
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Page/Page column 14-15
(2016/11/07)
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- Performance, Structure, and Mechanism of ReOx-Pd/CeO2 Catalyst for Simultaneous Removal of Vicinal OH Groups with H2
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The ceria-supported rhenium catalyst modified with palladium (ReOx-Pd/CeO2 (Re = 2 wt %, Pd/Re = 0.25)) is still the best catalyst for simultaneous hydrodeoxygenation. Higher Re loading amount decreased the activity. The simultaneous hydrodeoxygenation of cyclic vicinal diols occurs with high cis-stereoselectivity. ReOx-Pd/CeO2 catalysts were characterized by means of XRD, TEM, H2-TPR, XAFS, XPS, Raman, and DFT calculations. The Re species on ReOx-Pd/CeO2 (Re = 2 wt %, Pd/Re = 0.25) catalyst after reduction and after stoichiometric reaction of 1,2-hexanediol to 1-hexene were ReIV and ReVI, and the ReIV species were converted to ReVI through the stoichiometric reaction. The Re species on ReOx-Pd/CeO2 are proposed to be randomly located on the CeO2 surface, and probably only monomeric Re species have catalytic activity for simultaneous hydrodeoxygenation. This model can explain the higher activity of Re = 2 wt % catalyst than those of higher Re loading catalysts. The reaction is proposed to proceed by the tetra/hexavalent redox cycle of the Re center in the catalysis followed by hydrogenation.
- Ota, Nobuhiko,Tamura, Masazumi,Nakagawa, Yoshinao,Okumura, Kazu,Tomishige, Keiichi
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p. 3213 - 3226
(2016/07/06)
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