- Selective Preparation of 4-Alkylphenol from Lignin-Derived Phenols and Raw Biomass over Magnetic Co–Fe?N-Doped Carbon Catalysts
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Lignin valorization to produce high-value chemicals selectively is an enormous challenge in biorefinery. In this study, 4-alkylphenol, formed by breaking the robust Caryl?OCH3 bonds solely with the retention of other structures in lignin-derived methoxylalkylphenols, was produced selectively over a Co1–Fe0.1?NC catalyst from real lignin oil as feedstock, which was obtained by a “lignin-first” strategy from either birch or cornstalk. A yield of 64.7 or 88.3 mol % of 4-propylphenol was obtained if birch lignin oil or eugenol was used as the substrate, respectively. The catalysts were characterized by using methods that include Brunauer–Emmett–Teller measurements, XRD, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, and temperature-programmed desorption with synchrotron vacuum ultraviolet photoionization mass spectrometry. The results of catalyst characterization and comparison experiments indicated that CoNx was the main active phase for demethoxylation and hydrogenation, and the incorporation of Fe weakens the adsorption of 4-propylphenol to the catalyst, which inhibits the excessive hydrogenation of 4-propylphenol. This work shows the potential to produce high-value-added 4-alkylphenol from renewable raw biomass.
- Liu, Xiaohao,Wang, Chenguang,Zhang, Ying,Qiao, Yan,Pan, Yang,Ma, Longlong
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- Biomass-derived lignin to jet fuel range hydrocarbons via aqueous phase hydrodeoxygenation
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A catalytic process, involving the hydrodeoxygenation (HDO) of dilute alkali extracted corn stover lignin catalysed by noble metal catalyst (Ru/Al2O3) and acidic zeolite (H+-Y), to produce lignin-substructure-based hydrocarbons (C7-C18), primarily C12-C18 cyclic structure hydrocarbons in the jet fuel range, was demonstrated.
- Wang, Hongliang,Ruan, Hao,Pei, Haisheng,Wang, Huamin,Chen, Xiaowen,Tucker, Melvin P.,Cort, John R.,Yang, Bin
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- Integrated study on the role of solvent, catalyst and reactant in the hydrodeoxygenation of eugenol over nickel-based catalysts
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The hydrodeoxygenation (HDO) of phenols to hydrocarbons is a very promising technique process for the lignin valorization. To reveal the role of reactant, solvent and catalyst, the HDO experiments of eugenol to hydrocarbons were carried out at 523?K under 3?MPa H2over Ni catalysts supported on activated carbon (AC) and MFI-type zeolites in polar water and nonpolar n-hexane, respectively. It was found that Ni/AC was more efficient for the HDO of eugenol in water than in n-hexane, but Ni/HZSM-5 was just the opposite. The respective roles of Br?nsted acid sites and Lewis acid sites on supports were also investigated by employing NaZSM-5, HZSM-5 and silicalite-1 as supports. It was revealed that Br?nsted acid showed superior advantages (TOF: 37.9?h?1to 11.1?h?1) over Lewis acid in the dehydration of 4-propyl-cyclohexanol. Oxygen-containing functional groups could be removed from the aromatic ring completely over Ni/HZSM-5 in n-hexane.
- Qi, Jingbo,Sun, Xianyong,Tang, Si-Fu,Sun, Yuanyuan,Xu, Chen,Li, Xiaoyu,Li, Xuebing
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- A synergistic biorefinery based on catalytic conversion of lignin prior to cellulose starting from lignocellulosic biomass
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Current biomass utilization processes do not make use of lignin beyond its heat value. Here we report on a bimetallic Zn/Pd/C catalyst that converts lignin in intact lignocellulosic biomass directly into two methoxyphenol products, leaving behind the carbohydrates as a solid residue. Genetically modified poplar enhanced in syringyl (S) monomer content yields only a single product, dihydroeugenol. Lignin-derived methoxyphenols can be deoxygenated further to propylcyclohexane. The leftover carbohydrate residue is hydrolyzed by cellulases to give glucose in 95% yield, which is comparable to lignin-free cellulose (solka floc). New conversion pathways to useful fuels and chemicals are proposed based on the efficient conversion of lignin into intact hydrocarbons. This journal is
- Parsell, Trenton,Yohe, Sara,Degenstein, John,Jarrell, Tiffany,Klein, Ian,Gencer, Emre,Hewetson, Barron,Hurt, Matt,Kim, Jeong Im,Choudhari, Harshavardhan,Saha, Basudeb,Meilan, Richard,Mosier, Nathan,Ribeiro, Fabio,Delgass, W. Nicholas,Chapple, Clint,Kentt?maa, Hilkka I.,Agrawal, Rakesh,Abu-Omar, Mahdi M.
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Read Online
- Fabricating nickel phyllosilicate-like nanosheets to prepare a defect-rich catalyst for the one-pot conversion of lignin into hydrocarbons under mild conditions
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The one-pot conversion of lignin biomass into high-grade hydrocarbon biofuels via catalytic hydrodeoxygenation (HDO) holds significant promise for renewable energy. A great challenge for this route involves developing efficient non-noble metal catalysts to obtain a high yield of hydrocarbons under relatively mild conditions. Herein, a high-performance catalyst has been prepared via the in situ reduction of Ni phyllosilicate-like nanosheets (Ni-PS) synthesized by a reduction-oxidation strategy at room temperature. The Ni-PS precursors are partly converted into Ni0 nanoparticles by in situ reduction and the rest remain as supports. The Si-containing supports are found to have strong interactions with the nickel species, hindering the aggregation of Ni0 particles and minimizing the Ni0 particle size. The catalyst contains abundant surface defects, weak Lewis acid sites and highly dispersed Ni0 particles. The catalyst exhibits excellent catalytic activity towards the depolymerization and HDO of the lignin model compound, 2-phenylethyl phenyl ether (PPE), and the enzymatic hydrolysis of lignin under mild conditions, with 98.3% cycloalkane yield for the HDO of PPE under 3 MPa H2 pressure at 160 °C and 40.4% hydrocarbon yield for that of lignin under 3 MPa H2 pressure at 240 °C, and its catalytic activity can compete with reported noble metal catalysts.
- Cao, Meifang,Chen, Bo,He, Chengzhi,Ouyang, Xinping,Qian, Yong,Qiu, Xueqing
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supporting information
p. 846 - 857
(2022/02/09)
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- Aromatic compound hydrogenation and hydrodeoxygenation method and application thereof
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The invention belongs to the technical field of medicines, and discloses an aromatic compound hydrogenation and hydrodeoxygenation method under mild conditions and application of the method in hydrogenation and hydrodeoxygenation reactions of the aromatic compounds and related mixtures. Specifically, the method comprises the following steps: contacting the aromatic compound or a mixture containing the aromatic compound with a catalyst and hydrogen with proper pressure in a solvent under a proper temperature condition, and reacting the hydrogen, the solvent and the aromatic compound under the action of the catalyst to obtain a corresponding hydrogenation product or/and a hydrodeoxygenation product without an oxygen-containing substituent group. The invention also discloses specific implementation conditions of the method and an aromatic compound structure type applicable to the method. The hydrogenation and hydrodeoxygenation reaction method used in the invention has the advantages of mild reaction conditions, high hydrodeoxygenation efficiency, wide substrate applicability, convenient post-treatment, and good laboratory and industrial application prospects.
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Paragraph 0094-0095; 0123-0125; 0127-0130
(2021/05/29)
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- Chemoselective and Tandem Reduction of Arenes Using a Metal–Organic Framework-Supported Single-Site Cobalt Catalyst
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The development of heterogeneous, chemoselective, and tandem catalytic systems using abundant metals is vital for the sustainable synthesis of fine and commodity chemicals. We report a robust and recyclable single-site cobalt-hydride catalyst based on a porous aluminum metal–organic framework (DUT-5 MOF) for chemoselective hydrogenation of arenes. The DUT-5 node-supported cobalt(II) hydride (DUT-5-CoH) is a versatile solid catalyst for chemoselective hydrogenation of a range of nonpolar and polar arenes, including heteroarenes such as pyridines, quinolines, isoquinolines, indoles, and furans to afford cycloalkanes and saturated heterocycles in excellent yields. DUT-5-CoH exhibited excellent functional group tolerance and could be reusable at least five times without decreased activity. The same MOF-Co catalyst was also efficient for tandem hydrogenation–hydrodeoxygenation of aryl carbonyl compounds, including biomass-derived platform molecules such as furfural and hydroxymethylfurfural to cycloalkanes. In the case of hydrogenation of cumene, our spectroscopic, kinetic, and density functional theory (DFT) studies suggest the insertion of a trisubstituted alkene intermediate into the Co–H bond occurring in the turnover limiting step. Our work highlights the potential of MOF-supported single-site base–metal catalysts for sustainable and environment-friendly industrial production of chemicals and biofuels.
- Akhtar, Naved,Begum, Wahida,Chauhan, Manav,Manna, Kuntal,Newar, Rajashree,Rawat, Manhar Singh
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supporting information
(2022/01/19)
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- Improved Hydrodeoxygenation of Phenol to Cyclohexane on NiFe Alloy Catalysts Derived from Phyllosilicates
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A phyllosilicate-derived NiFe/SiO2 catalyst (NiFe/SiO2?AE) was successfully prepared by the ammonia evaporation method and applied in the hydrodeoxygenation of phenol to cyclohexane. Another two catalysts were also prepared for a comparison by impregnation (NiFe/SiO2?IM) and deposition-precipitation (NiFe/SiO2?DP) methods, respectively. It was found that Ni?Fe alloy, the active sites for the hydrogenolysis of C?O bond, can be obtained by the reduction of NiFe2O4 (IM) or phyllosilicate (DP and AE) by H2. The AE strategy can generate more phyllosilicate structure, which improves the dispersion of both Ni?Fe alloy and metallic Ni sites and allows the formation of more interface between these two kinds of sites as well. Therefore, the NiFe/SiO2?AE exhibits a significantly high catalytic performance in the HDO of phenol to cyclohexane. Moreover, the turnover frequency of Ni?Fe alloy sites over NiFe/SiO2?AE catalysts is much higher than those of other two catalysts. It is suggested that the enhanced synergy between the two kinds of active sites in the adsorption of C?O groups and hydrogen molecules ensures the superior intrinsic activity in HDO process.
- Han, Qiao,Wang, Hui,Rehman, Mooeez Ur,Shang, Xin,Chen, Haijun,Ji, Na,Tong, Xinli,Shi, Hui,Zhao, Yujun
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supporting information
p. 5069 - 5076
(2021/12/14)
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- The solvent determines the product in the hydrogenation of aromatic ketones using unligated RhCl3as catalyst precursor
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Alkyl cyclohexanes were synthesized in high selectivity via a combined hydrogenation/hydrodeoxygenation of aromatic ketones using ligand-free RhCl3 as pre-catalyst in trifluoroethanol as solvent. The true catalyst consists of rhodium nanoparticles (Rh NPs), generated in situ during the reaction. A range of conjugated as well as non-conjugated aromatic ketones were directly hydrodeoxygenated to the corresponding saturated cyclohexane derivatives at relatively mild conditions. The solvent was found to be the determining factor to switch the selectivity of the ketone hydrogenation. Cyclohexyl alkyl-alcohols were the products using water as a solvent.
- Bartling, Stephan,Chakrabortty, Soumyadeep,De Vries, Johannes G.,Kamer, Paul C. J.,Lund, Henrik,Müller, Bernd H.,Rockstroh, Nils
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p. 7608 - 7616
(2021/12/13)
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- Anionic Amphiphilic Cyclodextrins Bearing Oleic Grafts for the Stabilization of Ruthenium Nanoparticles Efficient in Aqueous Catalytic Hydrogenation
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Oleic succinyl β-cyclodextrin was proved to be efficient for the stabilization of ruthenium nanoparticles (NPs) in aqueous medium. These NPs were characterized by FTIR spectroscopy and transition electron microscopy (TEM). The catalytic activity of these NPs was evaluated in the aqueous hydrogenation of petrosourced and biosourced unsaturated compounds such as benzene and furfural derivatives. The catalytic system can be easily recycled and reused up to nine runs without any loss of activity and selectivity, demonstrating its robustness.
- Cocq, Aurélien,Léger, Bastien,No?l, Sébastien,Bricout, Hervé,Djeda?ni-Pilard, Florence,Tilloy, Sébastien,Monflier, Eric
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p. 1013 - 1018
(2019/12/27)
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- Effect of Zr on catalytic performance of unsupported Ni(Zr)Mo and Ni(Zr)W sulfide catalysts for quinoline hydrodenitrogenation
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To increase the dispersion of active species and full utilization of active metals are of great importance for hydrodenitrogenation (HDN) performance of unsupported hydrotreating catalysts. Herein, a series of unsupported Ni(Zr)MoS and Ni(Zr)WS catalysts were prepared from Ni(Zr) layered double hydroxide (LDH) precursors. The Zr species remarkably promote the dispersion and reducibility of NiMo and NiW composite species. Also, the total HDN rate constants are increased from 2.42 h?1 to 9.18 h?1 for Ni(Zr)MoS and from 5.68 h?1 to 23.0 h?1 for Ni(Zr)WS, and exhibit a maximum at a Zr/Ni atomic ratio of about 0.04. The HDN selectivities indicate that the Zr species increase the number of superficial active sites without affecting their structure. The present work shows that the crystallinity of LDH precursors is crucial to the structure of unsupported sulfide catalysts, and a suitable amount of Zr could be a dispersive promoter to increase the HDN activity.
- Jiang, Zongxuan,Li, Can,Liu, Tiefeng,Liu, Xinyi,Zhang, Cen
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- One-Pot Conversion of Lignin into Naphthenes Catalyzed by a Heterogeneous Rhenium Oxide-Modified Iridium Compound
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The direct transformation of lignin into fuels and chemicals remains a huge challenge because of the recalcitrant and complicated structure of lignin. In this study, rhenium oxide-modified iridium supported on SiO2 (Ir-ReOx/SiO2) is employed for the one-pot conversion of various lignin model compounds and lignin feedstocks into naphthenes. Up to 100 percent yield of cyclohexane from model compounds and 44.3 percent yield of naphthenes from lignin feedstocks are achieved. 2 D HSQC NMR spectroscopy before and after the reaction confirms the activity of Ir-ReOx/SiO2 in the cleavage of the C?O bonds and hydrodeoxygenation of the depolymerized products. H2 temperature-programmed reduction, temperature-programmed desorption of NH3, IR spectroscopy of pyridine adsorption, X-ray photoelectron spectroscopy, X-ray absorption fine structure analysis, and control experiments reveal that a synergistic effect between Ir and ReOx in Ir-ReOx/SiO2 plays a crucial role in the high performance; ReOx is mainly responsible for the cleavage of C?O bonds, whereas Ir is responsible for hydrodeoxygenation and saturation of the benzene rings. This methodology opens up an energy-efficient route for the direct conversion of lignin into valuable naphthenes.
- Li, Xinxin,Zhang, Bo,Pan, Xiaoli,Ji, Jianwei,Ren, Yujing,Wang, Hua,Ji, Na,Liu, Qiying,Li, Changzhi
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p. 4409 - 4419
(2020/03/04)
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- One-pot hydrodeoxygenation (HDO) of lignin monomers to C9 hydrocarbons co-catalysed by Ru/C and Nb2O5
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A physical mixture of Ru/C and Nb2O5 is an effective catalyst for upgrading lignin monomers under low H2 pressure at 250 °C to a clean cut of hydrocarbon liquid fuels. The reaction solvent is water with a small amount of methanol additive. Hydrodeoxygenation (HDO) was evaluated using dihydroeugenol (DHE) as an exemplary lignin monomer model. Under optimized conditions, 100% conversion of DHE and very high selectivity to propyl cyclohexane (C9 hydrocarbon) was achieved. Nb2O5 was prepared at a low temperature (450 °C) and was shown to contain acid sites that enhance the production of fully deoxygenated products. The methanol additive serves as a hydrogen source for the Ru/C catalysed reduction of the aromatic ring. In addition, when a substrate mixture of DHE, isoeugenol and 4-allylsyringol simulating lignin products was employed, 100% conversion to propyl cyclohexane (76%) and propyl benzene (24%) was observed, thereby suggesting the general applicability of this catalyst system for funneling lignin monomers into a clean cut of hydrocarbon liquid fuels. This study sheds light on the function of each catalyst component and provides a simple and green utilization of biomass monomers as a feedstock for renewable hydrocarbon fuels. This journal is
- Abu-Omar, Mahdi M.,Ford, Peter C.,Li, Simin,Liu, Baoyuan,Luo, Zhongyang,Truong, Julianne
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p. 7406 - 7416
(2020/11/25)
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- An efficient bifunctional Ru-NbOPO4 catalyst for the hydrodeoxygenation of aromatic ethers, phenols and real bio-oil
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An efficient bifunctional NbOPO4 supported Ru catalyst (Ru-NbOPO4) was applied to the hydrodeoxygenation of aromatic ethers and phenols and the upgrading of bio-oil. Characterization results revealed that the Ru-NbOPO4 catalyst possessed strong acidity, including Lewis and Br?nsted acids. The Lewis acid sites originated from the Nb[sbnd]O bonding structures, including slightly distorted octahedral NbO6, regular tetrahedral NbO4 and highly distorted octahedral NbO6. In combination with the strong acidity of the Nb[sbnd]O species and excellent hydrogenation activity of the metallic Ru, the bifunctional Ru-NbOPO4 catalyst exhibited an excellent catalytic activity in the hydrodeoxygenation of aromatic ethers and phenols with different structures, and even real bio-oil to alkanes. The hydrocarbon yield after real bio-oil upgradation was up to 88.2 %. Carbon deposition and enlargement of the Ru nanoparticles resulted in slight deactivation of the catalyst. The catalytic activity could be mostly recovered after being calcined and reduced.
- Zhao, Hongye,Hu, Xun,Hao, Jianxiu,Li, Na,Zhi, Keduan,He, Runxia,Wang, Yunfei,Zhou, Huacong,Liu, Quansheng
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- Liquid-phase Hydrodeoxygenation of 4-Propylphenol to Propylbenzene: Reducible Supports for Pt Catalysts
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Pyrolysis and liquefaction biocrudes obtained from lignocellulose are rich in phenolic compounds that can be converted to renewable aromatics. In this study, Pt catalysts on reducible metal oxide supports (Nb2O5, TiO2), along with irreducible ZrO2 as a reference, were investigated in the liquid-phase hydrodeoxygenation (HDO) of 4-propylphenol (350 °C, 20 bar H2, organic solvent). The most active catalyst was Pt/Nb2O5, which led to the molar propylbenzene selectivity of 77 percent, and a yield of 75 percent (98 percent conversion). Reducible metal oxide supports provided an increased activity and selectivity to the aromatic product compared to ZrO2, and the obtained results are among the best reported in liquid-phase. The reusability of the spent catalysts was also studied. The spent Pt/Nb2O5 catalyst provided the lowest conversion, while the product distribution of the spent Pt/ZrO2 catalyst changed towards oxygenates. The results highlight the potential of pyrolysis or liquefaction biocrudes as a source of aromatic chemicals.
- González Escobedo, José Luis,Karinen, Reetta,Lahtinen, Jouko,Lassi, Ulla,Lindblad, Marina,M?kel?, Eveliina,Neuvonen, Jouni,Puurunen, Riikka L.
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- Highly Efficient Cleavage of Ether Bonds in Lignin Models by Transfer Hydrogenolysis over Dual-Functional Ruthenium/Montmorillonite
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Cleavage of ether bonds is a crucial but challenging step for lignin valorization. To efficiently realize this transformation, the development of robust catalysts or catalytic systems is required. In this study, montmorillonite (MMT)-supported Ru (denoted as Ru/MMT) is fabricated as a dual-functional heterogeneous catalyst to cleave various types of ether bonds through transfer hydrogenolysis without using any additional acids or bases. The prepared Ru/MMT material is found to efficiently catalyze the cleavage of various lignin models and lignin-derived phenols; cyclohexanes (fuels) and cyclohexanols (key intermediates) are the main products. The synergistic effect between electron-enriched Ru and the acidic sites on MMT contributes to the excellent performance of Ru/MMT. Systematic studies reveal that the reaction proceeds through two possible reaction pathways, including the direct cleavage of ether bonds and the formation of intermediates with one hydrogenated benzene ring, for all examined types of ether bonds, namely, 4-O-5, α-O-4, and β-O-4.
- Xue, Zhimin,Yu, Haitao,He, Jing,Zhang, Yibin,Lan, Xue,Liu, Rundong,Zhang, Luyao,Mu, Tiancheng
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p. 4579 - 4586
(2020/06/21)
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- Efficient Conversion of Pine Wood Lignin to Phenol
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Obtaining chemical building blocks from biomass is attractive for meeting sustainability targets. Herein, an effective approach was developed to convert the lignin part of woody biomass into phenol, which is a valuable base chemical. Monomeric alkylmethoxyphenols were obtained from pinewood, rich in guaiacol-type lignin, through Pt/C-catalyzed reductive depolymerization. In a second step, an optimized MoP/SiO2 catalyst was used to selectively remove methoxy groups in these lignin monomers to generate 4-alkylphenols, which were then dealkylated by zeolite-catalyzed transalkylation to a benzene stream. The overall yield of phenol based on the initial lignin content in pinewood was 9.6 mol %.
- Boot, Michael D.,Hensen, Emiel J. M.,Huang, Xiaoming,Ouyang, Xianhong
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- Mechanistic study of the selective hydrogenation of carboxylic acid derivatives over supported rhenium catalysts
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The structure and performance of TiO2-supported Re (Re/TiO2) catalysts for selective hydrogenation of carboxylic acid derivatives have been investigated. Re/TiO2 promotes selective hydrogenation reactions of carboxylic acids and esters that form the corresponding alcohols, and of amides that generate the corresponding amines. These processes are not accompanied by reduction of aromatic moieties. A Re loading amount of 5 wt% and a catalyst pretreatment with H2 at 500 °C were identified as being optimal to obtain the highest catalytic activity for the hydrogenation processes. The results of studies using various characterization methods, including X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM), indicate that the Re species responsible for the catalytic hydrogenation processes have sub-nanometer to a few nanometer sizes and average oxidation states higher than 0 and below +4. The presence of either a carboxylic acid and/or its corresponding alcohol is critical for preventing the Re/TiO2 catalyst from promoting production of dearomatized byproducts. Although Re/TiO2 is intrinsically capable of hydrogenating aromatic rings, carboxylic acids, alcohols, amides, and amines strongly adsorb on the Re species, which leads to suppression of this process. Moreover, the developed catalytic system was applied to selective hydrogenation of triglycerides that form the corresponding alcohols.
- Toyao, Takashi,Ting, Kah Wei,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Maeno, Zen,Ariga-Miwa, Hiroko,Kanda, Yasuharu,Asakura, Kiyotaka,Shimizu, Ken-ichi
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p. 5413 - 5424
(2019/10/29)
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- Surface Modification of a Supported Pt Catalyst Using Ionic Liquids for Selective Hydrodeoxygenation of Phenols into Arenes under Mild Conditions
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The selective and efficient removal of oxygenated groups from lignin-derived phenols is a critical challenge to utilize lignin as a source for renewable aromatic chemicals. This report describes how surface modification of a zeolite-supported Pt catalyst using ionic liquids (ILs) remarkably increases selectivity for the hydrodeoxygenation (HDO) of phenols into arenes under mild reaction conditions using atmospheric pressure H2. Unmodified Pt/H-ZSM-5 converts phenols into aliphatic species as the major products along with a slight amount of arenes (10 % selectivity). In contrast, the catalyst modified with an IL, 1-butyl-3-methylimidazolium triflate, keeps up to 76 % selectivity for arenes even at a nearly complete conversion of phenols. The IL on the surface of Pt catalyst may offer the adsorption of phenols in an edge-to-face manner onto the surface, thus accelerating the HDO without the ring hydrogenation.
- Ohta, Hidetoshi,Tobayashi, Kanako,Kuroo, Akihiro,Nakatsuka, Mao,Kobayashi, Hirokazu,Fukuoka, Atsushi,Hamasaka, Go,Uozumi, Yasuhiro,Murayama, Haruno,Tokunaga, Makoto,Hayashi, Minoru
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supporting information
p. 14762 - 14766
(2019/11/13)
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- Iron-catalysed allylation-hydrogenation sequences as masked alkyl-alkyl cross-couplings
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An iron-catalysed allylation of organomagnesium reagents (alkyl, aryl) with simple allyl acetates proceeds under mild conditions (Fe(OAc)2 or Fe(acac)2, Et2O, r.t.) to furnish various alkene and styrene derivatives. Mechanistic studies indicate the operation of a homotopic catalyst. The sequential combination of such iron-catalysed allylation with an iron-catalysed hydrogenation results in overall C(sp3)-C(sp3)-bond formation that constitutes an attractive alternative to challenging direct cross-coupling protocols with alkyl halides.
- Bernauer, Josef,Wu, Guojiao,Von Wangelin, Axel
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p. 31217 - 31223
(2019/10/19)
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- CALCIUM SALTS-SUPPORTED METAL CATALYST, METHOD FOR PREPARING THE SAME, AND METHOD FOR HYDRODEOXYGENATION REACTION OF OXYGENATES USING THE SAME
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Disclosed herein are a calcium salts-supported metal catalyst, a method for preparing the same, and a method for the hydrodeoxygenation reaction of oxygenates using the same. The catalyst, in which a metal catalyst is supported on a carrier of a calcium salt, for example, calcium carbonate, has the effect of increasing the efficiency of hydrodeoxygenation reaction of oxygenates.
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Paragraph 0072; 0073; 0074
(2020/01/04)
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- CATALYTIC CONVERSION OF BIOMASS TO BIOPHENOL
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The invention relates to a demethoxylation process for demethoxylating alkylmethoxyphenols using an aromatic solvent to produce alkylphenols. The invention also relates to dealkylation process for dealkylating alkylphenols using an aromatic solvent to produce phenol. The invention further relates to a tandem demethoxylation and dealkylation process, which can be performed in a single reactor. The process is useful in the conversion of lignin derived alkylmethoxyphenols into biophenol.
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Page/Page column 20; 25
(2019/10/04)
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- Titanium(III)-Oxo Clusters in a Metal-Organic Framework Support Single-Site Co(II)-Hydride Catalysts for Arene Hydrogenation
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Titania (TiO2) is widely used in the chemical industry as an efficacious catalyst support, benefiting from its unique strong metal-support interaction. Many proposals have been made to rationalize this effect at the macroscopic level, yet the underlying molecular mechanism is not understood due to the presence of multiple catalytic species on the TiO2 surface. This challenge can be addressed with metal-organic frameworks (MOFs) featuring well-defined metal oxo/hydroxo clusters for supporting single-site catalysts. Herein we report that the Ti8(μ2-O)8(μ2-OH)4 node of the Ti-BDC MOF (MIL-125) provides a single-site model of the classical TiO2 support to enable CoII-hydride-catalyzed arene hydrogenation. The catalytic activity of the supported CoII-hydride is strongly dependent on the reduction of the Ti-oxo cluster, definitively proving the pivotal role of TiIII in the performance of the supported catalyst. This work thus provides a molecularly precise model of Ti-oxo clusters for understating the strong metal-support interaction of TiO2-supported heterogeneous catalysts.
- Ji, Pengfei,Song, Yang,Drake, Tasha,Veroneau, Samuel S.,Lin, Zekai,Pan, Xiandao,Lin, Wenbin
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p. 433 - 440
(2018/01/17)
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- Pyridine(diimine) Molybdenum-Catalyzed Hydrogenation of Arenes and Hindered Olefins: Insights into Precatalyst Activation and Deactivation Pathways
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Pyridine(diimine) molybdenum bis(olefin) and bis(alkyl) complexes were synthesized, characterized, and examined for their catalytic activity in the hydrogenation of benzene and a selection of substituted arenes. The molybdenum bis(alkyl) complex (4-tBu-iPrPDI)Mo(CH2SiMe3)2 (iPrPDI = 2,6-(2,6-(C(CH3)2H)2C6H3N=CMe)2C5H3N) exhibited the highest activity for the hydrogenation of benzene, producing cyclohexane in >98% yield at 23 °C under 4 atm of hydrogen after 48 h. Toluene and o-xylene were similarly hydrogenated to their respective cycloalkanes, with the latter yielding predominantly (79:21 dr) cis-1,2-dimethylcyclohexane. The molybdenum-catalyzed hydrogenation of naphthalene yielded tetralin exclusively, and this selectivity was maintained at higher H2 pressure. At 32 atm of H2, more hindered arenes such as monosubstituted benzenes, biphenyl, and m- and p-xylenes underwent hydrogenation with yields ranging between 20 and >98%. (4-tBu-iPrPDI)Mo(CH2SiMe3)2 was also a competent alkene hydrogenation catalyst, supporting stepwise reduction of benzene to cyclohexadiene and cyclohexene during molybdenum-catalyzed arene hydrogenation. Deuterium labeling studies for the molybdenum-catalyzed hydrogenation of benzene produced numerous isotopologues and stereoisomers of cyclohexane, indicating reversible hydride (deuteride) insertion/β-H(D) elimination, diene/olefin binding, and allylic C-H(D) activation during the reaction. The resting state of the catalyst under neat conditions was established as the η6-benzene complex (iPrPDI)Mo(η6-benzene). Under catalytic conditions, pyridine underwent C-H activation of the 2-position and furan underwent formal C-O oxidative addition to yield a "metallapyran". Both reactions were identified as important catalyst deactivation pathways for the attempted molybdenum-catalyzed hydrogenation of heteroarenes.
- Joannou, Matthew V.,Bezdek, Máté J.,Chirik, Paul J.
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p. 5276 - 5285
(2018/05/15)
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- Production of Cycloalkanes in Hydrodeoxygenation of Isoeugenol Over Pt- and Ir-Modified Bifunctional Catalysts
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Hydrodeoxygenation of isoeugenol was investigated at 200 °C under 3 MPa total pressure in dodecane as a solvent, in hydrogen, over bifunctional Pt- and Ir-modified Beta zeolites and mesoporous materials. As a comparison, Pt and Ir supported on Al2O3, SiO2 and mesoporous MCM-41 were also tested. The catalysts were characterized by XRD, CO pulse chemisorption, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption and FTIR pyridine adsorption desorption. The results revealed that the most active and selective catalyst was Pt-H-Beta-300, which exhibits the lowest acidity and largest crystal size of Beta zeolite among the studied Pt- and Ir-modified Beta zeolites. Complete conversion of isoeugenol and 89 % selectivity to propylcyclohexane was obtained with this catalyst in 240 min. The overall deoxygenation selectivity was 100 %, giving dialkylated cyclohexanes as the second major product. The catalyst was regenerated, reduced and reused in the hydrodeoxygenation of isoeugenol with almost the same performance as the fresh catalyst. Thermodynamic analyses and kinetic modelling of the data were also performed.
- Bomont, Louis,Alda-Onggar, Moldir,Fedorov, Vyacheslav,Aho, Atte,Peltonen, Janne,Er?nen, Kari,Peurla, Markus,Kumar, Narendra,W?rn?, Johan,Russo, Vincenzo,M?ki-Arvela, P?ivi,Grénman, Henrik,Lindblad, Marina,Murzin, Dmitry Yu.
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p. 2841 - 2854
(2018/07/06)
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- Efficient hydro-deoxygenation of lignin derived phenolic compounds over bifunctional catalysts with optimized acid/metal interactions
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Efficient hydro-deoxygenation (HDO) of lignin derived phenolic compounds was a challenging task due to the incompatibility of the phenolic feedstock and the current hydro-processing catalysts. In this paper, hydro-deoxygenation of lignin derived phenolic compounds over a series of bifunctional catalysts with different metal/acid interactions was firstly carried out. It was found that the distance between the acidic site and noble metal played an important role in the catalytic performance of phenolic hydro-deoxygenation. A highly stable bifunctional catalyst for hydro-deoxygenation of lignin derived phenolic compounds was obtained through simple selective deposition of Pt on alumina in a commonly used Al2O3-ZSM-5 nanocomposite. The bifunctional catalyst retained its complete deoxygenation capacity for more than 500 h. The catalyst can also be used for the HDO of various phenolic model compounds and real bio-oil derived from lignin. A correction of the generally accepted the closer the better criterion in metal/acid bifunctional catalysts when used in bio-oxygenate HDO was also discussed.
- Ju, Chao,Li, Mingrui,Fang, Yunming,Tan, Tianwei
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supporting information
p. 4492 - 4499
(2018/10/24)
-
- Effects of Sugars, Furans, and their Derivatives on Hydrodeoxygenation of Biorefinery Lignin-Rich Wastes to Hydrocarbons
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Hydrodeoxygenation of biorefinery lignin-rich wastes to jet fuel hydrocarbons offers a significant opportunity for enhancing the overall operational efficiency, carbon conversion efficiency, economic viability, and sustainability of biofuels production. However, these wastes usually mainly contain lignin with sugars, furans, and their derivatives as “impurities”. Although several factors, including reactant structure, solvents, or the decreased ratio of catalyst to reactant, could be responsible for the jet fuel hydrocarbons yield loss, we found evidence that glucose, xylose, and 5-hydroxymethylfurfural dramatically decreased conversion yields. For example, xylose and glucose lowered the final hydrocarbon yield by 78 and 63 %, respectively. The results revealed that these compounds could suppress metal catalysts and inhibit lignin depolymerization and hydrodeoxygenation (HDO) reactions thus decrease yields of jet fuel range hydrocarbons from biomass-derived lignin. The first-principles calculations and TGA results from spent catalysts validated these findings.
- Wang, Hongliang,Duan, Yuhua,Zhang, Qian,Yang, Bin
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p. 2562 - 2568
(2018/08/01)
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- Production of Jet Fuel-Range Hydrocarbons from Hydrodeoxygenation of Lignin over Super Lewis Acid Combined with Metal Catalysts
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Super Lewis acids containing the triflate anion [e.g., Hf(OTf)4, Ln(OTf)3, In(OTf)3, Al(OTf)3] and noble metal catalysts (e.g., Ru/C, Ru/Al2O3) formed efficient catalytic systems to generate saturated hydrocarbons from lignin in high yields. In such catalytic systems, the metal triflates mediated rapid ether bond cleavage through selective bonding to etheric oxygens while the noble metal catalyzed subsequent hydrodeoxygenation (HDO) reactions. Near theoretical yields of hydrocarbons were produced from lignin model compounds by the combined catalysis of Hf(OTf)4 and ruthenium-based catalysts. When a technical lignin derived from a pilot-scale biorefinery was used, more than 30 wt % of the hydrocarbons produced with this catalytic system were cyclohexane and alkylcyclohexanes in the jet fuel range. Super Lewis acids are postulated to strongly interact with lignin substrates by protonating hydroxyl groups and ether linkages, forming intermediate species that enhance hydrogenation catalysis by supported noble metal catalysts. Meanwhile, the hydrogenation of aromatic rings by the noble metal catalysts can promote deoxygenation reactions catalyzed by super Lewis acids.
- Wang, Hongliang,Wang, Huamin,Kuhn, Eric,Tucker, Melvin P.,Yang, Bin
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p. 285 - 291
(2017/11/20)
-
- Slowing the Kinetics of Alumina Sol–Gel Chemistry for Controlled Catalyst Overcoating and Improved Catalyst Stability and Selectivity
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Catalyst overcoating is an emerging approach to engineer surface functionalities on supported metal catalyst and improve catalyst selectivity and durability. Alumina deposition on high surface area material by sol–gel chemistry is traditionally difficult to control due to the fast hydrolysis kinetics of aluminum-alkoxide precursors. Here, sol–gel chemistry methods are adapted to slow down these kinetics and deposit nanometer-scale alumina overcoats. The alumina overcoats are comparable in conformality and thickness control to overcoats prepared by atomic layer deposition even on high surface area substrates. The strategy relies on regulating the hydrolysis/condensation kinetics of Al(sBuO)3 by either adding a chelating agent or using nonhydrolytic sol–gel chemistry. These two approaches produce overcoats with similar chemical properties but distinct physical textures. With chelation chemistry, a mild method compatible with supported base metal catalysts, a conformal yet porous overcoat leads to a highly sintering-resistant Cu catalyst for liquid-phase furfural hydrogenation. With the nonhydrolytic sol–gel route, a denser Al2O3 overcoat can be deposited to create a high density of Lewis acid–metal interface sites over Pt on mesoporous silica. The resulting material has a substantially increased hydrodeoxygenation activity for the conversion of lignin-derived 4-propylguaiacol into propylcyclohexane with up to 87% selectivity.
- Du, Yuan-Peng,Héroguel, Florent,Luterbacher, Jeremy S.
-
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- Liquid phase hydrodeoxygenation of anisole, 4-ethylphenol and benzofuran using Ni, Ru and Pd supported on USY zeolite
-
The objective of this work is to understand the role of metals on the hydrodeoxygenation (HDO) reaction pathways of three bio-oil model compounds. Ni, Ru and Pd were impregnated on USY zeolite, and the catalysts were characterized to determine metal reduction profile, surface concentration and nanoparticle size. Ru-USY and Pd-USY were completely reduced at a temperature below 450 °C, but Ni-USY still contained surface metal oxides after reduction. There was no indication of strong interactions between the metals and USY support. Anisole, 4-ethylphenol and benzofuran were used as bio-oil model compounds, in order to determine the effects of each metal on deoxygenation of methoxy-, phenol and furan functional groups, respectively. Pd-USY was the most effective HDO catalyst, exhibiting the highest turnover frequency for HDO of all three model compounds, in addition to and high selectivity to deoxygenated products. A mechanism was proposed for each model compound, and the kinetics of hydrogenation, dehydration, C–C coupling and ring-opening reactions were determined.
- Gamliel, David P.,Karakalos, Stavros,Valla, Julia A.
-
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- Effective hydrodeoxygenation of lignin-derived phenols using bimetallic RuRe catalysts: Effect of carbon supports
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We have previously shown that an activated carbon-supported ruthenium catalyst promoted with ReOx (RuRe/AC) is highly active for the hydrodeoxygenation (HDO) of lignin-derived phenols (e.g., guaiacol). In this work, we have investigated the effect of carbon supports on the structure and HDO activity of bimetallic RuRe particles using three different carbon supports, i.e., activated carbon (AC), carbon black (Vulcan carbon, VC), multi-walled carbon nanotube (MWCNT). The MWCNT- and VC-supported catalysts show remarkably enhanced activity and hydrocarbon selectivity for the HDO of a range of phenolic molecules (i.e., guaiacol, eugenol, benzyl phenyl ether) compared to RuRe/AC. STEM-EDS and XPS analyses reveal that bimetallic RuRe particles are more common than monometallic Ru or Re particles in the VC- and MWCNT-supported catalysts, and hexavalent rhenium species are more easily reduced to tetravalent rhenium during the HDO reactions in these catalysts, suggesting that Ru and Re in close proximity are required for the efficient hydrogenolysis of phenols. The formation of bimetallic particles on the AC surface is likely hindered by high microporosity and high surface oxygen functionalities, both of which restrict the mobility of Re and Ru for assembly.
- Jung, Kyung Bin,Lee, Jinho,Ha, Jeong-Myeong,Lee, Hyunjoo,Suh, Dong Jin,Jun, Chul-Ho,Jae, Jungho
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p. 191 - 199
(2017/09/06)
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- Quinoline Hydrodenitrogenation over NiW/Al-MCM-41 Catalysts with Different Al Contents
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Al-MCM-41 materials were prepared with different Al contents and used as supports for NiW catalysts. The supports and catalysts were characterized by XRD, N2 adsorption-desorption, XPS, Raman, H2-TPR techniques. The XPS result showed that the Al added to MCM-41 promoted the dispersion of W and Ni species. The Raman result showed that the Al added to MCM-41 favored the formation of the suitable W species. The H2-TPR result showed that the Al added to MCM-41 can reduce the reduction temperature of W species on the catalysts. The hydrodenitrogenation (HDN) results showed that the HDN activity followed the order of NiW/Al-2 > NiW/Al-1 > NiW/Al-4 > NiW. Moreover, this tendency was also valid for the ratio of propylcyclohexane/propylbenzene (PCH/PB). The high HDN activity and PCH/PB ratio of NiW/Al-2 are due to the well dispersion of the W and Ni species, the suitable W species and the low reduction temperature of W species.
- Guo, Fang,Li, Jun,Li, Wanxi,Chen, Xiuling,Qi, Hongxue,Wang, Xiaoxiao,Yu, Yue
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p. 2055 - 2063
(2018/05/22)
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- Simultaneous hydrodenitrogenation and hydrodesulfurization on unsupported Ni-Mo-W sulfides
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The catalytic properties of unsupported Ni-Mo-W sulfides (composites of Ni-Mo(W)S2 mixed sulfides and Ni3S2) obtained from precursors synthesized via co-precipitation, hydrothermal, and thiosalt decomposition were explored
- Albersberger, Sylvia,Hein, Jennifer,Schreiber, Moritz W.,Guerra, Santiago,Han, Jinyi,Gutiérrez, Oliver Y.,Lercher, Johannes A.
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p. 344 - 355
(2017/09/30)
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- TiO2-Supported Re as a General and Chemoselective Heterogeneous Catalyst for Hydrogenation of Carboxylic Acids to Alcohols
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TiO2-supported Re, Re/TiO2, was found to promote selective hydrogenation of carboxylic acids having aromatic and aliphatic moieties to the corresponding alcohols. Re/TiO2showed superior results compared to other transition-metal-loaded TiO2and supported Re catalysts for selective hydrogenation of 3-phenylpropionic acid. 3-phenylpropanol was produced in 97 % yield under mild conditions (5 MPa H2at 140 °C). Contrary to typical heterogeneous catalysts, Re/TiO2does not lead to the formation of dearomatized byproducts. The catalyst is recyclable and shows a wide substrate scope in the synthesis of alcohols (22 examples; up to 97 % isolated yield).
- Toyao, Takashi,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Kon, Kenichi,Morita, Yoshitsugu,Kamachi, Takashi,Yoshizawa, Kazunari,Shimizu, Ken-Ichi
-
supporting information
p. 1001 - 1006
(2017/02/05)
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- Preparation and characterization of NiW supported on Al-modified MCM-48 catalyst and its high hydrodenitrogenation activity and stability
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Al-containing MCM-48 with different Si/Al ratios and aluminum free MCM-48 materials were successfully prepared with hexadecyl trimethyl ammonium bromide (CTAB) and poly(ethylene oxide) poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (P123) as a co-template. A series of characterizations show that both the supports and the NiW supported catalysts are highly ordered. The acid strength of the supports is enhanced when Al is introduced and when its content is increased. The acid amount and strength is further improved by supporting the NiW species. The oxide precursors show a high degree of sulfidation under mild sulfidation conditions. The activity of the Al-modified catalysts for quinoline hydrodenitrogenation (HDN) is much higher than that of aluminum free NiW/MCM-48 and NiW/γ-Al2O3 catalysts. The addition of CS2 to the feed could boost the conversion of quinoline HDN and change the product distribution due to modification of the active site distribution of hydrogenation and C-N bond cleavage. Moreover, the stability of the resulting catalysts was also investigated, and no dramatic decrease in HDN conversion was observed in 960 h, which suggests that they could be candidates for industrial HDN catalysts.
- Shao, Mingqiang,Cui, Haitao,Guo, Shaoqing,Zhao, Liangfu,Tan, Yisheng
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p. 61747 - 61757
(2016/07/11)
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- Selective hydrodeoxygenation of lignin-derived phenols to alkyl cyclohexanols over a Ru-solid base bifunctional catalyst
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Cyclohexanol and alkyl cyclohexanol are important chemical intermediates. It is meaningful to prepare cyclohexanols from non-fossil-based biomass. Here we report Ru/ZrO2-La(OH)3, a metal-solid base bifunctional catalyst, to show its excellent performance on the partial hydrodeoxygenation of lignin-derived phenols. Guaiacol could be converted to cyclohexanol with a 91.6% yield in water. Alkyl phenols with one or two methoxy groups were converted into alkyl cyclohexanols with yields over 86.9%. The catalyst had good activity of removing a methoxy group and retaining a hydroxyl group. In this catalyst, Zr and La interacted with each other to form a mixed (hydr)oxide, thus making ZrO2-La(OH)3 a stable support. Ru was highly dispersed on the ZrLa support. The pathway from guaiacol to cyclohexanol was investigated and proposed as two parallel ways, demethoxylation followed by hydrogenation (I), the saturation of the aromatic ring through hydrogenation and then demethoxylation through direct hydrogenolysis (II).
- Xu, Guang-Yue,Guo, Jian-Hua,Qu, Yan-Chao,Zhang, Ying,Fu, Yao,Guo, Qing-Xiang
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p. 5510 - 5517
(2016/10/21)
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- Selective Hydrodeoxygenation of Lignin-Derived Phenols to Cyclohexanols or Cyclohexanes over Magnetic CoNx@NC Catalysts under Mild Conditions
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The hydrodeoxygenation (HDO) of lignin-derived phenols is important to produce the renewable biofuels. Herein, we reported a simple method to prepare magnetic nitrogen-doped carbon supported cobalt nitride catalysts (CoNx@NC) by copyrolysis of cellulose and cobalt nitrate under ammonia atmosphere. The catalysts were prepared at different temperatures and characterized by elemental analysis, atomic absorption spectroscopy (AAS), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and temperature-programmed reduction (TPR). The CoNx@NC-650 (pyrolyzed at 650°C) exhibited the best HDO activity for eugenol conversion among a series of Co-based catalysts. The yield of propylcyclohexanol from eugenol was >99.9% under 2 MPa H2 at 200°C for 2 h. Moreover, a high yield of propylcyclohexane (99.1%) could be achieved when the solid acid HZSM-5 was added to the reaction system. Other lignin-derived phenolic compounds were also investigated and the yield of alkanes was >90%. Based on the mechanism investigation, the catalyst demonstrated a high selectivity to cleave the Caryl-OR bond under mild conditions. (Chemical Equation Presented).
- Liu, Xiaohao,Xu, Lujiang,Xu, Guangyue,Jia, Wenda,Ma, Yanfu,Zhang, Ying
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p. 7611 - 7620
(2016/11/17)
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- Enhancing the Catalytic Properties of Ruthenium Nanoparticle-SILP Catalysts by Dilution with Iron
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The partial replacement of ruthenium by iron ("dilution") provided enhanced catalytic activities and selectivities for bimetallic iron-ruthenium nanoparticles immobilized on a supported ionic liquid phase (FeRuNPs@SILP). An organometallic synthetic approach to the preparation of FeRuNPs@SILP allowed for a controlled and flexible incorporation of Fe into bimetallic FeRu NPs. The hydrogenation of substituted aromatic substrates using bimetallic FeRuNPs@SILP showed high catalytic activities and selectivities for the reduction of a variety of unsaturated moieties without saturation of the aromatic ring. The formation of a bimetallic phase not only leads to an enhanced differentiation of the hydrogenation selectivity, but even reversed the order of functional group hydrogenation in certain cases. In particular, bimetallic FeRuNPs@SILP (Fe:Ru = 25:75) were found to exhibit accelerated reaction rates for C=O hydrogenation within furan-based substrates which were >4 times faster than monometallic RuNPs@SILP. Thus, the controlled incorporation of the non-noble metal into the bimetallic phase provided novel catalytic properties that could not be obtained using either of the monometallic catalysts.
- Luska, Kylie L.,Bordet, Alexis,Tricard, Simon,Sinev, Ilya,Grünert, Wolfgang,Chaudret, Bruno,Leitner, Walter
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p. 3719 - 3726
(2016/07/06)
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- Production of liquid hydrocarbon fuels with acetoin and platform molecules derived from lignocellulose
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Acetoin, a novel C4 platform molecule derived from new ABE (acetoin-butanol-ethanol) type fermentation via metabolic engineering, was used for the first time as a bio-based building block for the production of liquid hydrocarbon fuels. A series of diesel or jet fuel range C9-C14 straight, branched, or cyclic alkanes were produced in excellent yields by means of C-C coupling followed by hydrodeoxygenation reactions. Hydroxyalkylation/alkylation of acetoin with 2-methylfuran was investigated over a series of solid acid catalysts. Among the investigated candidates, zirconia supported trifluoromethanesulfonic acid showed the highest activity and stability. In the aldol condensation step, a basic ionic liquid [H3N+-CH2-CH2-OH][CH3COO-] was identified as an efficient and recyclable catalyst for the reactions of acetoin with furan based aldehydes. The scope of the process has also been studied by reacting acetoin with other aldehydes, and it was found that abnormal condensation products were formed from the reactions of acetoin with aromatic aldehydes through an aldol condensation-pinacol rearrangement route when amorphous aluminium phosphate was used as a catalyst. And the final hydrodeoxygenation step could be achieved by using a simple and handy Pd/C + H-beta zeolite system, and no or a negligible amount of oxygenates was observed after the reaction. Excellent selectivity was also observed using the present system, and the clean formation of hydrocarbons with a narrow distribution of alkanes occurred in most cases.
- Zhu, Chenjie,Shen, Tao,Liu, Dong,Wu, Jinglan,Chen, Yong,Wang, Linfeng,Guo, Kai,Ying, Hanjie,Ouyang, Pingkai
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p. 2165 - 2174
(2016/04/19)
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- Hydrodeoxygenation of lignin-derived phenols into alkanes over carbon nanotube supported Ru catalysts in biphasic systems
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Phenolic compounds derived from lignin are important feedstocks for the sustainable production of alkane fuels with C6-C9 carbons. Hydrodeoxygenation (HDO) is the main chemical process to remove oxygen-containing functionalities. Here, we have reported the HDO of phenols in a biphasic H2O/n-dodecane system. A series of supported Ru catalysts were prepared, characterized and explored for the reaction among which Ru/CNT showed the highest catalytic activity towards the production of alkanes. The model reaction with eugenol achieved a high conversion (>99%) and a high alkane selectivity (98%), which was much higher than the results from the monophasic system (56.5% yield of alkanes in H2O). The reaction conditions including reaction temperature, hydrogen pressure and the ratio of H2O/n-C12H26 were optimized. The kinetic experiments revealed that eugenol was first hydrogenated to 4-propyl-guaiacol, and then deoxygenated into 4-propyl-cyclohexanol which was the main detected intermediate of the reaction. After that, 4-propyl-cyclohexanol was dehydrated and hydrogenated into propylcyclohexane. Moreover, various phenols and dimeric lignin model compounds were also successfully converted into alkanes in the biphasic systems. The construction of the biphasic solvent-Ru/CNT catalyst system highlights an efficient route for the conversion of lignin-derived phenolic compounds to biofuels.
- Chen, Meng-Yuan,Huang, Yao-Bing,Pang, Huan,Liu, Xin-Xin,Fu, Yao
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p. 1710 - 1717
(2015/03/18)
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- Low temperature hydrodeoxygenation of phenols under ambient hydrogen pressure to form cyclohexanes catalysed by Pt nanoparticles supported on H-ZSM-5
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The hydrodeoxygenation of various phenols to form cyclohexanes was achieved at 110 °C under an H2 atmosphere at ambient pressure using a Pt/H-ZSM-5 catalyst and octane as the solvent.
- Ohta, Hidetoshi,Yamamoto, Kentaro,Hayashi, Minoru,Hamasaka, Go,Uozumi, Yasuhiro,Watanabe, Yutaka
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p. 17000 - 17003
(2015/11/27)
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- Selective hydrogenolysis of phenols and phenyl ethers to arenes through direct C-O cleavage over ruthenium-tungsten bifunctional catalysts
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Direct hydrogenolysis of the aromatic Csp2-O bonds in both phenols and phenyl ethers to form arenes selectively is a core enabling technology that can expand greatly the scope of chemical manufacture from biomass. However, conventional hydrogenolysis of phenols typically led to aromatic ring saturation instead of the cleavage of the Csp2-O bonds. Herein, we report a recyclable Ru-WOx bifunctional catalyst that showed high catalytic activities for the hydrogenolysis of a wide range of phenols and phenyl ethers, including dimeric lignin model compounds and the primitive phenols separated from pyrolysis lignin, to form arenes selectively in water. Preliminary mechanistic studies supported that the reactions occurred via a direct cleavage of the Csp2-O bonds and the concerted effects of the hydrogenating Ru sites and the Lewis acidic W sites are the key to such an unusual reactivity.
- Huang, Yao-Bing,Yan, Long,Chen, Meng-Yuan,Guo, Qing-Xiang,Fu, Yao
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p. 3010 - 3017
(2015/05/27)
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- Effect of ZrO2 in Ni2P/ZrO2-Al2O3 catalysts on hydrotreating reactions
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Catalysts 60% Ni/Al2O3 and 60% Ni/4% ZrO2-Al2O3 were prepared, and it was found that the addition of ZrO2 promoted reduction while maintaining the high dispersion of supported nickel. Upon phosphidation by triphenylphosphine (PPh3) in the liquid phase, the two catalysts were converted into corresponding Ni2P/Al2O3 and Ni2P/ZrO2-Al2O3 catalysts with highly dispersed Ni2P particles (6.3 and 6.8 nm, respectively), high CO uptakes (305 and 328 μmol g-1, respectively) and thus high activities for the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation of tetralin to decalin. In particular, the Ni2P/ZrO2-Al2O3 was found to be significantly more active than the Ni2P/Al2O3 for the HDS of DBT and hydrogenation of tetralin to decalin. Although the presence of ZrO2 did not affect the heat of adsorption of CO on Ni2P, it significantly increased the heat and uptake of adsorption of H2 on Ni2P, which might account for the increased activity of Ni2P promoted by ZrO2.
- Wang, Junen,Yuan, Yamei,Shuaib, Abdalla,Xu, Jun,Shen, Jianyi
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p. 74312 - 74319
(2015/09/21)
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- Production of alkanes from lignin-derived phenolic compounds over in situ formed Ni catalyst with solid acid
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In situ formed Ni catalyst combined with added solid acids is highly active for the hydrodeoxygenation of lignin-derived phenolic compounds. In the heterogeneous catalysts, in situ formed Ni acts as the hydrogenation and hydrogenolysis catalyst and solid acid acts as the dehydration catalyst.
- Zhang, Xinghua,Wang, Tiejun,Zhang, Qi,Xu, Ying,Long, Jinxing,Chen, Lungang,Wang, Chenguang,Ma, Longlong
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supporting information
p. 648 - 650
(2015/05/20)
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- Mesoporous ZSM-5 zeolite-supported ru nanoparticles as highly efficient catalysts for upgrading phenolic biomolecules
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Zeolite-based catalysts have been widely used in the conversion of biomass recently, but the catalytic yields of the desired products are strongly limited by the relatively small micropores of zeolite. Here, we reported a hierarchically porous ZSM-5 zeolite with micropore and b-axis-aligned mesopore-supported Ru nanoparticles (Ru/HZSM-5-OM) that are highly efficient for the hydrodeoxygenation of both small and bulky phenolic biomolecules to the corresponding alkanes. Compared with the conventional ZSM-5 zeolite-supported Ru catalyst, the high catalytic activities and alkane selectivities over Ru/HZSM-5-OM are attributed to the abundant exposed acidic sites in HZSM-5-OM with open mesopores. This feature is potentially important for future phenolic bio-oil upgrading.
- Wang, Liang,Zhang, Jian,Yi, Xianfeng,Zheng, Anmin,Deng, Feng,Chen, Chunyu,Ji, Yanyan,Liu, Fujian,Meng, Xiangju,Xiao, Feng-Shou
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p. 2727 - 2734
(2015/05/13)
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- Highly Selective Hydrogenation of Aromatic Ketones and Phenols Enabled by Cyclic (Amino)(alkyl)carbene Rhodium Complexes
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Air-stable Rh complexes ligated by strongly σ-donating cyclic (amino)(alkyl)carbenes (CAACs) show unique catalytic activity for the selective hydrogenation of aromatic ketones and phenols by reducing the aryl groups. The use of CAAC ligands is essential for achieving high selectivity and conversion. This method is characterized by its good compatibility with unsaturated ketones, esters, carboxylic acids, amides, and amino acids and is scalable without detriment to its efficiency.
- Wei, Yu,Rao, Bin,Cong, Xuefeng,Zeng, Xiaoming
-
supporting information
p. 9250 - 9253
(2015/08/11)
-
- Distribution of Metal Cations in Ni-Mo-W Sulfide Catalysts
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The distribution of metal cations and the morphology of unsupported NiMo, NiW, and NiMoW sulfide catalysts were explored qualitatively and quantitatively. In the bi- and trimetallic catalysts, Mo(W)S2 nanoparticles are deposited on Ni sulfide particles of varying stoichiometry and sizes (crystalline Ni9S8, and Ni3S4 were identified). These nanoparticles are stacks of Mo(W)S2 slabs with varying size, degrees of bending and mismatch between the slabs. High resolution electron microscopy and X-ray absorption spectroscopy based on particle modeling revealed a statistical distribution of Mo and W within individual layers in sulfide NiMoW, forming intralayer mixed Mo1-xWxS2. Ni is associated with MoS2, WS2, and Mo1-xWxS2 creating Ni-promoted phases. The incorporation of Ni at the edges of the slabs was the highest for sulfide NiMoW. This high concentration of Ni in sulfide NiMoW, as well as its long bent Mo1-xWxS2 slabs, were paralleled by the highest activity for nitrogen and sulfur removal from model hydrocarbons such as o-propylaniline and dibenzothiophene.
- Hein, Jennifer,Gutiérrez, Oliver Y.,Schachtl, Eva,Xu, Pinghong,Browning, Nigel D.,Jentys, Andreas,Lercher, Johannes A.
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p. 3692 - 3704
(2015/12/05)
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- γ-Al2O3-supported and unsupported (Ni)MoS 2 for the hydrodenitrogenation of quinoline in the presence of dibenzothiophene
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Supported MoS2/γ-Al2O3 and Ni-MoS2/γ-Al2O3 as well as unsupported Ni-MoS2 were investigated in the hydrodenitrogenation (HDN) of quinoline in the presence of dibenzothiophene (DBT). The supported oxide catalyst precursors had a well-dispersed amorphous polymolybdate structure that led to the formation of a highly dispersed sulfide phase. In contrast, the unsupported catalyst precursor consisted of a mixture of nickel molybdate and ammonium nickel molybdate phases that formed stacked sulfide slabs after sulfidation. On all catalysts, the reaction pathway for the removal of N in quinoline HDN mainly followed the sequence quinoline→1,2,3,4- tetrahydroquinoline→decahydroquinoline→propylcyclohexylamine→ propylcyclohexene→propylcyclohexane. The hydrodesulfurization of DBT proceeded mainly by direct desulfurization towards biphenyl. For both processes, the activity increased in the order MoS2/γ-Al 2O32/unsupported2/γ-Al2O3. The promotion of the MoS 2 phase with Ni enhances the activity of the unsupported catalyst to a greater extent than the supported one. However, the multiply stacked unsupported Ni-MoS2 exhibited lower rates than Ni-MoS 2/γ-Al2O3 because of its lower dispersion. I want to break free (from your nitrogen): Ni and Al 2O3 exert particular effects on the physicochemical and kinetic features of molybdenum oxide species and the corresponding MoS 2 phase. The support maximizes the concentration of active sites, whereas the promoter changes their intrinsic activity. In turn, the support also influences the promotion mechanism. Copyright
- Hein, Jennifer,Hrabar, Ana,Jentys, Andreas,Gutierrez, Oliver Y.,Lercher, Johannes A.
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p. 485 - 499
(2014/03/21)
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- Cyclodextrin-based systems for the stabilization of metallic(0) nanoparticles and their versatile applications in catalysis
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In order to better respond to environmental standards, the development of metal nanoparticles using green approaches has exponentially grown for the last decade. Cyclodextrins, which are cyclic oligosaccharides composed of 6(α), 7(β) or 8(γ) glucopyranose units, have appeared to be interesting candidates for the synthesis of metal nanoparticles. Indeed, through the ability to form inclusion complexes or supramolecular adducts with organic molecules or metal precursors, cyclodextrins can be successfully employed to stabilize size-controlled zerovalent metallic nanoparticles active for hydrogenation reactions carried out in aqueous or gas-phase media. In this summary of our works, we report that cyclodextrins could be used in various forms and environments: (i) in free form, (ii) in complexed form with appropriate guests molecules, (iii) in combination with polymer matrices, (iv) in thermosensitive hydrogels and (v) immobilized onto porous carbons supports. All these studies highlight the fact that cyclodextrins can be seen as multi-task agents for nanocatalysis.
- No?l, Sébastien,Léger, Bastien,Ponchel, Anne,Philippot, Karine,Denicourt-Nowicki, Audrey,Roucoux, Alain,Monflier, Eric
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- Increasing the aromatic selectivity of quinoline hydrogenolysis using Pd/MOx-Al2O3
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Catalysts consisting of Pd nanoparticles supported on highly dispersed TiOx-Al2O3, TaOx-Al2O3, and MoOx-Al2O3 are studied for catalytic quinoline hydrogenation and selective C-N bond cleavage at 275°C and 20 bar H2. The Pd/MOx-Al2O3 materials exhibit significantly greater aromatic product selectivity and thus 10-15 % less required H2 for a given level of denitrogenation relative to an unmodified Pd/Al2O3 catalyst.
- Bachrach, Mark,Morlanes-Sanchez, Natalia,Canlas, Christian P.,Miller, Jeffrey T.,Marks, Tobin J.,Notestein, Justin M.
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p. 1832 - 1838
(2015/02/19)
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