112-92-5Relevant articles and documents
Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica-Supported Ir–ReOx Bimetallic Catalyst
Liu, Sibao,Simonetti, Trent,Zheng, Weiqing,Saha, Basudeb
, p. 1446 - 1454 (2018)
High yields of diesel-range alkanes are prepared by hydrodeoxygenation of vegetable oils and waste cooking oils over ReOx-modified Ir/SiO2 catalysts under mild reaction conditions. The catalyst containing a Re/Ir molar ratio of 3 exhibits the best performance, achieving 79–85 wt % yield of diesel-range alkanes at 453 K and 2 MPa H2. The yield is nearly quantitative for the theoretical possible long-chain alkanes on the basis of weight of the converted oils. The catalyst retains comparable activity upon regeneration through calcination. Control experiments using probe molecules as model substrates suggest that C=C bonds of unsaturated triglycerides and free fatty acids are first hydrogenated to their corresponding saturated intermediates, which are then converted to aldehyde intermediates through hydrogenolysis of acyl C?O bonds and subsequently hydrogenated to fatty alcohols. Finally, long-chain alkanes without any carbon loss are formed by direct hydrogenolysis of the fatty alcohols. Small amounts of alkanes with one carbon fewer are also formed by decarbonylation of the aldehyde intermediates. A synergy between Ir and partially reduced ReOx sites is discussed to elucidate the high activity of Ir–ReOx/SiO2.
Permeable composite membrane as a catalytically active contactor for hydrogenation reactions
Minyukova, T. P.,Shtertser, N. V.,Khassin, A. A.,Yurieva, T. M.
, p. 107 - 110,4 (2012)
The efficiency of using of the permeable composite membrane (PCM) is demonstrated in the 3-phase reaction of liquid substrate with gaseous hydrogen on solid catalyst (PCM acts as a catalytically active contactor) - hydrogenation of fatty acid triglyceride. PCM provides a good combination of the opposite requirements of mild internal diffusion restrictions, low hydraulic resistance, high thermal conductivity, well-developed gas-liquid interface and high catalyst loading in the reactor volume, and thus assures the control of the course of the catalytic reaction.
Influence of the operating conditions and kinetic analysis of the selective hydrogenation of oleic acid on Ru-Sn-B/Al2O3 catalysts
Sánchez, María A.,Pouilloux, Yannick,Mazzieri, Vanina A.,Pieck, Carlos L.
, p. 552 - 558 (2013)
The influence of the operating conditions on the selectivity and activity of Ru-Sn-B/Al2O3 catalysts for the hydrogenation of oleic acid to oleyl alcohol was studied. It was found that the Ru-Sn-B/Al 2O3 catalyst is selective to oleyl alcohol while Ru or Ru-B/Al2O3 catalysts are not selective to produce oleyl alcohol. The electronic and catalytic properties of Ru are modified by the strong interaction between Sn and B. The incorporation of Sn leads to catalysts capable of producing oleyl alcohol. The experiments of oleic acid hydrogenation showed that an increase in reaction temperature leads to an increase in activity while the selectivity to oleyl alcohol goes through a maximum. This is because the reactions of hydrogenation of CC double bond have lower activation energies than hydrogenolytic reactions. The increase in operating pressure has a positive effect on conversion and a more important effect on selectivity. A very simple first order kinetic model is proposed and reasonably represents the results obtained. This model can be useful to compare catalyst performance more rationally.
Kinetics of hydrodeoxygenation of stearic acid using supported nickel catalysts: Effects of supports
Kumar, Pankaj,Yenumala, Sudhakara Reddy,Maity, Sunil K.,Shee, Debaprasad
, p. 28 - 38 (2014)
The hydrodeoxygenation of fatty acids derived from vegetable and microalgal oils is a novel process for production of liquid hydrocarbon fuels well-suited with existing internal combustion engines. The hydrodeoxygenation of stearic acid was investigated in a high pressure batch reactor using n-dodecane as solvent over nickel metal catalysts supported on SiO2, γ-Al2O3, and HZSM-5 in the temperature range of 533-563 K. Several supported nickel oxide catalysts with nickel loading up to 25 wt.% were prepared by incipient wetness impregnation method and reduced using hydrogen. The catalysts were then characterized by BET, TPR, H2 pulse chemisorption, TPD, XRD, and ICP-AES. Characterization studies revealed that only dispersed nickel oxide was present up to 15 wt.% nickel loading on γ-Al2O3. The acidity of the supports depends on nickel loading of oxidized catalysts and increases with increasing nickel loading up to 15 wt.%. n-Pentadecane, n-hexadecane, n-heptadecane, n-octadecane, and l-octadecanol were identified as products of hydrodeoxygenation of stearic acid with n-heptadecane being primary product. The catalytic activity and selectivity to products for hydrodeoxygenation of stearic acid depends strongly on acidity of the supports. The maximum selectivity to n-heptadecane was observed with nickel supported γ-Al2O3 catalyst. A suitable reaction mechanism of hydrodeoxygenation of stearic acid was delineated based on products distribution. The conversion of stearic acid was increased with increasing reaction time, nickel loading on γ-Al2O 3, temperature, and catalyst loading. Complete conversion of stearic acid was accomplished with more than 80% selectivity to n-heptadecane at reasonable reaction temperature of 563 K after 240 min of reaction using 15 wt.% Ni/γ-Al2O3 catalyst. An empirical kinetic model was also developed to correlate the experimental data.
An efficient hydrogenation catalytic model hosted in a stable hyper-crosslinked porous-organic-polymer: From fatty acid to bio-based alkane diesel synthesis
Sarkar, Chitra,Shit, Subhash Chandra,Dao, Duy Quang,Lee, Jihyeon,Tran, Ngoc Han,Singuru, Ramana,An, Kwangjin,Nguyen, Dang Nam,Le, Quyet Van,Amaniampong, Prince Nana,Drif, Asmaa,Jerome, Francois,Huyen, Pham Thanh,Phan, Thi To Nga,Vo, Dai-Viet N.,Thanh Binh, Nguyen,Trinh, Quang Thang,Sherburne, Matthew P.,Mondal, John
, p. 2049 - 2068 (2020)
In this study, a Pd-based catalytic model over a nitrogen enriched fibrous Porous-Organic-Polymer (POP) is established to execute hydrodeoxygenation of various vegetable oils in producing potential large-scale renewable diesel. Here we report a cost-effective synthesis strategy for a new microporous hypercrosslinked POP through the FeCl3 assisted Friedel-Crafts alkylation reaction, followed by fabrication of Pd0-NPs (2-3 nm) using a solid gas phase hydrogenation route to deliver a novel catalytic system. This catalyst (called Pd@PPN) exhibits versatile catalytic performance for different types of vegetable oils including palm oil, soybean oil, sunflower oil and rapeseed oil to furnish long chain diesel range alkanes. The catalyst is comprehensively characterized using various spectroscopic tools and it shows high stability during five runs of recycling without leaching of Pd. Our results further reveal that a direct decarbonylation (DCN) pathway of fatty acids to produce alkanes with one fewer carbon is the dominant mechanism. Under optimized conditions, using stearic acid to represent the long linear carboxylic acids in the vegetable oils, up to 90% conversion with 83% selectivity of C17-alkane has been achieved on our fabricated catalyst. Density functional theory (DFT) calculations are performed to provide insights into the electronic properties of the catalyst, the mechanistic reaction pathway, the crucial role of the catalyst surface and the product selectivity trend. The strong interaction between the corrugated polymer-frame-structure and the Pd-NPs suggests the presence of high density step sites on the fabricated Pd-NP anchored within the cage of the polymer structure. DFT calculations also reveal the strong promotional effect of step sites and charge transfer in facilitating rate-limiting steps during the decarbonylation (DCN) pathway and removal of strongly bound intermediates formed during the process, therefore explaining the high activity of the fabricated Pd@PPN catayst for the hydrodeoxygenation (HDO) conversion to produce bio-based alkane diesel.
Impact of the oxygen defects and the hydrogen concentration on the surface of tetragonal and monoclinic ZrO2 on the reduction rates of stearic acid on Ni/ZrO2
Foraita, Sebastian,Fulton, John L.,Chase, Zizwe A.,Vjunov, Aleksei,Xu, Pinghong,Barth, Eszter,Camaioni, Donald M.,Zhao, Chen,Lercher, Johannes A.
, p. 2423 - 2434 (2015)
The role of the specific physicochemical properties of ZrO2 phases on Ni/ZrO2 has been explored with respect to the reduction of stearic acid. Conversion on pure m-ZrO2 is 1.3 times more active than on t-ZrO2, whereas Ni/m-ZrO2 is three times more active than Ni/t-ZrO2. Although the hydrodeoxygenation of stearic acid can be catalyzed solely by Ni, the synergistic interaction between Ni and the ZrO2 support causes the variations in the reaction rates. Adsorption of the carboxylic acid group on an oxygen vacancy of ZrO2 and the abstraction of the a-hydrogen atom with the elimination of the oxygen atom to produce a ketene is the key to enhance the overall rate. The hydrogenated intermediate 1-octadecanol is in turn decarbonylated to heptadecane with identical rates on all catalysts. Decarbonylation of 1-octadecanol is concluded to be limited by the competitive adsorption of reactants and intermediate. The substantially higher adsorption of propionic acid demonstrated by IR spectroscopy and the higher reactivity to O2 exchange reactions with the more active catalyst indicate that the higher concentration of active oxygen defects on m-ZrO2 compared to t-ZrO2 causes the higher activity of Ni/m-ZrO2.
In situ hydrogenation and decarboxylation of oleic acid into heptadecane over a Cu-Ni alloy catalyst using methanol as a hydrogen carrier
Zhang, Zihao,Yang, Qiwei,Chen, Hao,Chen, Kequan,Lu, Xiuyang,Ouyang, Pingkai,Fu, Jie,Chen, Jingguang G.
, p. 197 - 206 (2018)
In this work, supported Cu-Ni bimetallic catalysts were synthesized and evaluated for the in situ hydrogenation and decarboxylation of oleic acid using methanol as a hydrogen donor. The supported Cu-Ni alloy exhibited a significant improvement in both activity and selectivity towards the production of heptadecane in comparison with monometallic Cu and Ni based catalysts. The formation of the Cu-Ni alloy is demonstrated by high-angle annular dark-field scanning transmission electron microscopy (HADDF-STEM), energy dispersive X-ray spectroscopy (EDS-mapping), X-ray diffraction (XRD) and temperature programmed reduction (TPR). A partially oxidized Cu in the Cu-Ni alloy is revealed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) following CO adsorption and X-ray photoelectron spectroscopy (XPS). The temperature programmed desorption of ethylene and propane (ethylene/propane-TPD) suggested that the formation of the Cu-Ni alloy inhibited the cracking of C-C bonds compared to Ni, and remarkably increased the selectivity to heptadecane. The temperature programmed desorption of acetic acid (acetic acid-TPD) indicated that the bimetallic Cu-Ni alloy and Ni catalysts had a stronger adsorption of acetic acid than that of the Cu catalyst. The formation of the Cu-Ni alloy and a partially oxidized Cu facilitates the decarboxylation reaction and inhibits the cracking reaction of C-C bonds, leading to enhanced catalytic activity and selectivity.
New bioactive sulfated metabolites from the Mediterranean tunicate Sidnyum turbinatum
Aiello,Carbonelli,Fattorusso,Iuvone,Menna
, p. 219 - 221 (2001)
In addition to the known sodium 3,7,11,15-tetramethylhexadeca-1,19-diyl sulfate (4), the BuOH extract of the Mediterranean tunicate Sidnyum turbinatum was shown to contain four new metabolites: 1-heptadecanyl sulfate (1), 1-octadecanyl sulfate (2), sodium
Tulloch,Spencer
, p. 2868 (1972)
Catalytic production of 1-octadecanol from octadecanoic acid by hydrotreating in a plug flow reactor
Potts, Thomas M.,Durant, Keiron,Hestekin, Jamie,Beitle, Robert,Ackerson, Michael
, p. 1643 - 1650,8 (2014)
1-Octadecanol (stearic alcohol) has uses ranging from lubricants to perfumes. The production of 1-octadecanol from octadecanoic acid (stearic acid) was investigated in a liquid-phase trickle-bed reactor by hydrogenating octadecanoic acid using a Ni/Co/Mo sulfide catalyst. The primary reactions occurring in the reactor were the desired conversion of octadecanoic acid to 1-octadecanol and the subsequent undesired conversion of 1-octadecanol to octadecane. A model was developed to predict these two reactions. The model found to be most useful for this system was a series-parallel reaction first order in octadecanoic acid and 1-octadecanol and pseudo-zero order in hydrogen for both reactions. The activation energies of the first and second reactions were 63.7.8 and 45.6 kJ/mol, respectively. From these values, the conversion of octadecanoic acid and the selectivity to the desired product as functions of temperature, space velocity, and inlet octadecanoic acid concentration were estimated. The model predicts the maximum productivity of 1-octadecanol occurs at higher temperatures with short residence times. Parametric plots show productivity to be ≥0.48 g 1-octadecanol/g octadecanoic acid at 566 °F and a 0.1 h residence time.
Hydrodeoxygenation of Palmitic and Stearic Acids on Phosphide Catalysts Obtained In Situ in Reaction Medium
Golubeva,Maksimov
, p. 1326 - 1330 (2019)
Abstract: Unsupported phosphide catalysts of composition Ni2P and CoP are prepared in situ in the reaction medium from oil-soluble precursors in the course of hydrodeoxygenation of palmitic and stearic acids. The obtained catalysts are characterized by X-ray powder diffraction and X-ray photoelectron spectroscopy; they show high activity in the hydrodeoxygenation of model substrates. After 6 h of the hydrodeoxygenation reactions, the conversion of palmitic acid reaches 93 and 92% and the conversion of stearic acid is as high as 94 and 91% in the presence of nickel phosphide and cobalt phosphide, respectively. It is shown that the catalyst formed in situ can be isolated and recycled.
Balancing the efficacy vs. the toxicity of promiscuous natural products: Paclitaxel-based acid-labile lipophilic prodrugs as promising chemotherapeutics
Chittiboyina, Amar G.,Claudio, Pier Paolo,Haider, Saqlain,McChesney, James D.,Penfornis, Patrice
, (2021/10/19)
TumorSelect is an anticancer technology that combines cytotoxics, nanotechnology, and knowledge of human physiology to develop innovative therapeutic interventions with minimal undesirable side effects commonly observed in conventional chemotherapy. Tumors have a voracious appetite for cholesterol which facilitates tumor growth and fuels their proliferation. We have transformed this need into a stealth delivery system to disguise and deliver anticancer drugs with the assistance of both the human body and the tumor cell. Several designer prodrugs are incorporated within pseudo-LDL nanoparticles, which carry them to tumor tissues, are taken up, internalized, transformed into active drugs, and inhibit cancer cell proliferation. Highly lipophilic prodrug conjugates of paclitaxel suitable for incorporation into the pseudo-LDL nanoparticles of the TumorSelect delivery vehicle formulation were designed, synthesized, and evaluated in the panel of 24-h NCI-60 human tumor cell line screening to demonstrate the power of such an innovative approach. Taxane prodrugs, viz., ART-207 was synthesized by tethering paclitaxel to lipid moiety with the aid of a racemic solketal as a linker in cost-effective, simple, and straightforward synthetic transformations. In addition to the typical 24-h NCI screening protocol, these compounds were assessed for growth inhibition or killing of ovarian cell lines for 48 and 72h-time intervals and identified the long-lasting effectiveness of these lipophilic prodrugs. All possible, enantiomerically pure isomers of ART-207 were also synthesized, and cytotoxicities were biosimilar to racemic ART-207, suggesting that enantiopurity of linker has a negligible effect on cell proliferation. To substantiate further, ART-207 was evaluated for its in vivo tumor reduction efficacy by studying the xenograft model of ovarian cancer grown in SCID mice. Reduced weight loss (a measure of toxicity) in the ART-207 group was observed, even though it was dosed at 2.5x the paclitaxel equivalent of Abraxane. As a result, our delineated approach is anticipated to improve patient quality of life, patient retention in treatment regimes, post-treatment rapid recovery, and overall patient compliance without compromising the efficacy of the cytotoxic promiscuous natural products.
Enantiomeric synthesis of natural alkylglycerols and their antibacterial and antibiofilm activities
Fernández Montoya, Deicy J.,Contreras Jordan, Luis A.,Moreno-Murillo, Bárbara,Silva-Gómez, Edelberto,Mayorga-Wandurraga, Humberto
supporting information, p. 2544 - 2550 (2019/11/13)
Alkylglycerols (AKGs) are bioactive natural compounds that vary by alkyl chain length and degree of unsaturation, and their absolute configuration is 2S. Three AKGs (5l–5n) were synthesised in enantiomerically pure form, and were characterised for the first time together with 12 other known and naturally occurring AKGs (5a–5k, 5o). Their structures were established using 1H and 13C APT NMR with 2D-NMR, ESI-MS or HRESI-MS and optical rotation data, and they were tested for their antibacterial and antibiofilm activities. AKGs 5a–5m and 5o showed activity against five clinical isolates and P. aeruginosa ATCC 15442, with MIC values in the range of 15–125 μg/mL. In addition, at half of the MIC, most of the AKGs reduced S. aureus biofilm formation in the range of 23%–99% and P. aeruginosa ATCC 15442 biofilm formation in the range of 14%–64%. The antibiofilm activity of the AKGs assessed in this work had not previously been studied.
Selective upgrading of biomass-derived benzylic ketones by (formic acid)–Pd/HPC–NH2 system with high efficiency under ambient conditions
Chen, Yuzhuo,Chen, Zhirong,Gong, Yutong,Mao, Shanjun,Ning, Honghui,Wang, Yong,Wang, Zhenzhen
, p. 3069 - 3084 (2021/11/16)
Upgrading biomass-derived phenolic compounds provides a valuable approach for the production of higher-value-added fuels and chemicals. However, most established catalytic systems display low hydrodeoxygenation (HDO) activities even under harsh reaction conditions. Here, we found that Pd supported on –NH2-modified hierarchically porous carbon (Pd/HPC–NH2) with formic acid (FA) as hydrogen source exhibits unprecedented performance for the selective HDO of benzylic ketones from crude lignin-derived oxygenates. Designed experiments and theoretical calculations reveal that the H+/H? species generated from FA decomposition accelerates nucleophilic attack on carbonyl carbon in benzylic ketones and the formate species formed via the esterification of intermediate alcohol with FA expedites the cleavage of C–O bonds, achieving a TOF of 152.5 h?1 at 30°C for vanillin upgrading, 15 times higher than that in traditional HDO processes (～10 h?1, 100°C–300°C). This work provides an intriguing green route to produce transportation fuels or valuable chemicals from only biomass under mild conditions.
