124-29-8Relevant academic research and scientific papers
Effect of precursor on the catalytic properties of Ni2P/SiO2 in methyl palmitate hydrodeoxygenation
Shamanaev, Ivan V.,Deliy, Irina V.,Aleksandrov, Pavel V.,Gerasimov, Evgeny Yu.,Pakharukova, Vera P.,Kodenev, Evgeny G.,Ayupov, Artem B.,Andreev, Andrey S.,Lapina, Olga B.,Bukhtiyarova, Galina A.
, p. 30372 - 30383 (2016)
The effect of phosphorus precursor on the physicochemical and catalytic properties of silica-supported nickel phosphide catalysts in the hydrodeoxygenation (HDO) of aliphatic model compound methyl palmitate (C15H31COOCH3) has been considered. Nickel aceta
Optimization of enzymatic synthesis of cetyl 2-ethylhexanoate by Novozym 435
Chen, Hsiao Ching,Kuo, Chia-Hung,Chen, Hsin Hung,Liu, Yung-Chuan,Shieh, Chwen Jen
, p. 1917 - 1923 (2011)
Waxes are esters obtained from long-chain fatty acids and long-chain alcohols which are biodegradable, biocompatible and nontoxic. Seafowl feather oil is a natural wax ester that exists on seafowl feathers. Cetyl 2-ethylhexanoate is the major ingredient of seafowl feather oil. Cetyl 2-ethylhexanoate is widely used in cosmetics as a base oil because of its lubricity, moisture retention and non-toxic properties. An optimal production of cetyl 2-ethylhexanoate by direct esterification of cetyl alcohol with 2-ethylhexanoic acid was developed using an immobilized lipase (Novozym 435) as a catalyst in n-hexane. Response surface methodology (RSM) and 5-level-4-factor central composite rotatable design (CCRD) were employed to evaluate the effects of reaction time, reaction temperature, substrate molar ratio, and enzyme amount on the yield of cetyl 2-ethylhexanoate. The results show that reaction time, reaction temperature, substrate molar ratio, and enzyme amount have significant effects on the yield of the esterification reaction. On the basis of ridge-max analysis, the optimum conditions were as follows: a reaction time of 2.65 days, a reaction temperature of 56.18 °C, a substrate molar ratio of 2.55:1, and an enzyme amount of 251.39%. The predicted and experimental values of molar conversion were 91.95 and 89.75 ± 1.06%, respectively. AOCS 2011.
Hydrodeoxygenation (HDO) of methyl palmitate over bifunctional Rh/ZrO2 catalyst: Insights into reaction mechanism via kinetic modeling
Bie, Yuwei,Lehtonen, Juha,Kanervo, Jaana
, p. 183 - 190 (2016)
Hydrodeoxygenation (HDO) of triglycerides into hydrocarbons is a novel catalytic process for the production of green biofuels. In this work, the HDO reaction mechanism over Rh/ZrO2 catalyst was studied by selecting methyl palmitate as a model compound. HDO of methyl palmitate proceeded initially via the hydrogenolysis into palmitic acid intermediate, followed by sequential hydrogenation-decarbonylation reaction into pentadecane via aldehyde intermediate. Bifunctional mechanism of the Rh/ZrO2 catalyst is advocated for the HDO process, in which both Rh sites and oxygen vacancy sites on ZrO2 synergistically contribute to the catalysis. The interface between Rh nanoparticle and support was proposed to host the most active sites. Based on our earlier work, a surface reaction mechanism was proposed and slightly modified to develop a set of mechanistic kinetic models. The mechanistic model consisting of two distinct types of adsorption sites for oxygenated components and H2, gave a good fitting to the kinetic data over a broad range of reaction conditions and conversion levels.
Paving the way towards green catalytic materials for green fuels: Impact of chemical species on Mo-based catalysts for hydrodeoxygenation
Valencia, Diego,Díaz-García, Leonardo,Ramírez-Verduzco, Luis Felipe,Qamar, Amir,Moewes, Alexander,Aburto, Jorge
, p. 18292 - 18301 (2019)
A series of Mo-based catalysts were synthesized by tuning the sulfidation temperature to produce mixtures of MoO3 and MoS2 as active phases for the hydrodeoxygenation (HDO) of palmitic acid. Differences in the oxidation states of Mo, and the chemical species present in the catalytic materials were determined by spectroscopic techniques. Palmitic acid was used as a fatty-acid model compound to test the performance of these catalysts. The catalytic performance was related to different chemical species formed within the materials. Sulfidation of these otherwise inactive catalysts significantly increased their performance. The catalytic activity remains optimal between the sulfidation temperatures of 100 °C and 200 °C, whereas the most active catalyst was obtained at 200 °C. The catalytic performance decreased significantly at 400 °C due to a higher proportion of sulfides formed in the materials. Furthermore, the relative proportion of MoO3 to MoS2 is essential to form highly active materials to produce O-free hydrocarbons from biomass feedstock. The transition from MoS2 to MoO3 reveals the importance of Mo-S and Mo-O catalytically active species needed for the HDO process and hence for biomass transformation. We conclude that transitioning from MoS2 to MoO3 catalysts is a step in the right direction to produce green fuels.
Ni-Based heterogeneous catalysts for the transformation of fatty acids into higher yields of O-free hydrocarbons
Aburto, Jorge,Gómez-Pérez, María Teresa,Gómora-Herrera, Diana,Valencia, Diego,Zenteno, Citlalli
, p. 3470 - 3480 (2020)
A series of novel catalytic materials were synthesized by changing the chemical compounds in the impregnation solutions. A rigid, aromatic and bidentate molecule 1,10-phenanthroline (PhN) was used as a ligand to bind Ni2+species prior to impregnation into a mesoporous KIT-5 support. Thein situsynthesized coordination compounds were impregnated into KIT-5 and the resulting materials exhibited better dispersion of metal species, being the best at a molar ratio Ni?:?PhN = 1?:?1. The materials were tested in the hydrodeoxygenation (HDO) of palmitic acid. We found that highly active and stable catalysts were obtained when using PhN as a chelating agent in the impregnation solution. The selectivity of these materials is remarkable since only O-free molecules were detected in the HDO products. Therefore, Ni-PhN complexes in combination with mesoporous SiO2can be further exploited for the catalytic transformation of biomass feedstocks.
Manipulating catalytic pathways: Deoxygenation of palmitic acid on multifunctional catalysts
Peng, Baoxiang,Zhao, Chen,Kasakov, Stanislav,Foraita, Sebastian,Lercher, Johannes A.
, p. 4732 - 4741 (2013)
The mechanism of the catalytic reduction of palmitic acid to n-pentadecane at 260 °C in the presence of hydrogen over catalysts combining multiple functions has been explored. The reaction involves rate-determining reduction of the carboxylic group of palmitic acid to give hexadecanal, which is catalyzed either solely by Ni or synergistically by Ni and the ZrO2 support. The latter route involves adsorption of the carboxylic acid group at an oxygen vacancy of ZrO2 and abstraction of the α-H with elimination of O to produce the ketene, which is in turn hydrogenated to the aldehyde over Ni sites. The aldehyde is subsequently decarbonylated to n-pentadecane on Ni. The rate of deoxygenation of palmitic acid is higher on Ni/ZrO2 than that on Ni/SiO2 or Ni/Al2O3, but is slower than that on H-zeolite-supported Ni. As the partial pressure of H2 is decreased, the overall deoxygenation rate decreases. In the absence of H 2, ketonization catalyzed by ZrO2 is the dominant reaction. Pd/C favors direct decarboxylation (-CO2), while Pt/C and Raney Ni catalyze the direct decarbonylation pathway (-CO). The rate of deoxygenation of palmitic acid (in units of mmol moltotal metal -1 h-1) decreases in the sequence r (Pt black)≈r(Pd black)>r(Raney Ni) in the absence of H2. In situ IR spectroscopy unequivocally shows the presence of adsorbed ketene (Ci?￡34;Ci?￡34;O) on the surface of ZrO2 during the reaction with palmitic acid at 260 °C in the presence or absence of H2. Biomass to biofuels: The conversion of palmitic acid to n-pentadecane over ZrO2 mainly proceeds by hydrogenation of the carboxylic acid group to give hexadecanal (rate-determining step), which is catalyzed either solely by Ni sites or synergistically by Ni sites and sites on the ZrO2 support (see scheme). In the absence of H2, ketonization is the dominant reaction catalyzed by ZrO 2. Copyright
A NEW METHOD FOR DEPROTECTION OF METHYLTHIOMETHYL ETHERS
Chowdhury, P K,Sharma, R P,Baruah, J N
, p. 4485 - 4486 (1983)
Methylthiomethyl ethers of primary, secondary and tertiary alcohols are efficiently cleaved by trityl tetrafluoroborate whereas that of phenols remain uneffected under the reaction conditions.
Ultra-low loading of Ni in catalysts supported on mesoporous SiO2 and their performance in hydrodeoxygenation of palmitic acid
Valencia, Diego,Zenteno, Citlalli,Morales-Gil, Perla,Díaz-García, Leonardo,Gómora-Herrera, Diana,Palacios-González, Eduardo,Aburto, Jorge
, p. 2435 - 2441 (2020)
We synthesized a series of new Ni catalysts supported on mesoporous silica KIT-5. The metal loading on this support was varied (0.9-7.0 wt% NiO). The catalysts were characterized by N2 physisorption, powder XRD, XRF spectrometry, UV-vis DRS, H2-TPR, HRTEM and FT-IR with CO. The mesoporous structure is maintained in all the catalytic materials. The increase in the Ni loading resulted in the formation of crystalline phases at the KIT-5 surface. The catalysts were tested in hydrodeoxygenation (HDO) of palmitic acid. The catalytic activity increased with the metal loading, reaching a maximum by using the catalyst with 1.8 wt% NiO. On the other hand, calculation of kinetic parameters indicated the effective utilization of catalytically active Ni particles in the HDO process. Formation of oxygen-free products was higher for the catalyst with higher metal loading in this series. These catalytic materials were compared with a series of Ni catalysts supported on carbon, finding that the Ni/KIT-5 catalysts were much more active in the HDO reaction. These new catalysts supported on the mesoporous silica KIT-5 exhibited high activity with low metal loadings. This feature makes them attractive for their application in the HDO of fatty acids.
New observations on deprotection of O-benzyl derivatives with Pd/C-cyclohexene
Sansanwal,Krishnamurty
, p. 1901 - 1906 (1995)
Palladium catalysed transfer hydrogenation using cyclohexene as the donor is found to deprotect readily alcohol benzyl ethers and aliphatic benzyl esters. The phenol benzyl ethers and benzyl benzoates are stable under these conditions.
Cetyl myristoleate isolated from Swiss albino mice: An apparent protective agent against adjuvant arthritis in rats
Diehl,May
, p. 296 - 299 (1994)
Cetyl myristoleate was isolated from National Institutes of Health, general purpose, Swiss albino mice that were immune to the polyarthritis induced in rats with Freund's adjuvant. This substance, or material synthesized from cetyl alcohol and myristoleic acid, afforded good protection against adjuvant-induced arthritic states in rats. In limited comparisons, cetyl oleate, also found in Swiss albino mice, gave lesser protection, whereas cetyl myristate and cetyl elaidate, the trans-isomer of cetyl oleate, appeared to be virtually ineffective. Dosage of the protective compound as well as the site of injection of Freund's adjuvant was important.
