629-78-7Relevant articles and documents
Bio-diesel production from deoxygenation reaction over Ce0.6Zr0.4O2 supported transition metal (Ni, Cu, Co, and Mo) catalysts
Shim, Jae-Oh,Jeong, Dae-Woon,Jang, Won-Jun,Jeon, Kyung-Won,Jeon, Byong-Hun,Kim, Seong-Heon,Roh, Hyun-Seog,Na, Jeong-Geol,Han, Sang Sup,Ko, Chang Hyun
, p. 4587 - 4592 (2016)
Ce0.6Zr0.4O2 supported transition metal (Me = Ni, Cu, Co, and Mo) catalysts have been investigated to screen for the catalytic activity and selectivity for deoxygenation reaction of oleic acid. Me - Ce0.6Zr0.4O2 catalysts were prepared by a co-precipitation method. Ni - Ce0.6Zr0.4O2 catalyst exhibited much higher oleic acid conversion, selectivity for C9 to C17 compounds, and oxygen removal efficiency than the others. This is mainly ascribed to the presence of free Ni species, synergy effects between Ni and Ce0.6Zr0.4O2, and the highest BET surface area.
Revealing the Influence of Silver in Ni–Ag Catalysts on the Selectivity of Higher Olefin Synthesis from Stearic Acid
Danyushevsky, V. Ya.,Murzin, V. Yu.,Kuznetsov,Shamsiev,Katsman,Khramov,Zubavichus,Berenblyum
, p. 57 - 65 (2018)
Results on the conversion of stearic acid to olefins over Ni–Ag/γ-Al2O3 catalysts are presented. XANES and EXAFS experiments in situ and DFT calculations were applied to reveal the structure of active sites therein. It is shown that the introduction of Ag to Ni catalysts leads to an increase in the olefin yield. After a reduction in hydrogen (350°C, 3 h) alumina-supported nanoparticles of nickel sulfides and metallic Ag are formed. The role of metal hydrides formed during the reaction is extensively discussed.
Insights into substrate and metal binding from the crystal structure of cyanobacterial aldehyde deformylating oxygenase with substrate bound
Buer, Benjamin C.,Paul, Bishwajit,Das, Debasis,Stuckey, Jeanne A.,Marsh, E. Neil G.
, p. 2584 - 2593 (2014)
The nonheme diiron enzyme cyanobacterial aldehyde deformylating oxygenase, cADO, catalyzes the highly unusual deformylation of aliphatic aldehydes to alkanes and formate. We have determined crystal structures for the enzyme with a long-chain water-soluble aldehyde and medium-chain carboxylic acid bound to the active site. These structures delineate a hydrophobic channel that connects the solvent with the deeply buried active site and reveal a mode of substrate binding that is different from previously determined structures with long-chain fatty acids bound. The structures also identify a water channel leading to the active site that could facilitate the entry of protons required in the reaction. NMR studies examining 1-[13C]-octanal binding to cADO indicate that the enzyme binds the aldehyde form rather than the hydrated form. Lastly, the fortuitous cocrystallization of the metal-free form of the protein with aldehyde bound has revealed protein conformation changes that are involved in binding iron.
Effect of promotion of nickel sulfide catalyst with silver on kinetics of decarbonilation of stearic acid
Katsman,Berenblyum,Danyushevsky, V. Ya.,Karpov,Kuznetsov,Leont′eva,Flid
, p. 2224 - 2229 (2018)
The kinetics of liquid-phase decarbonylation of stearic acid in n-dodecane on γ-Al2O3 supported nickel sulfide catalyst promoted with silver was experimentally studied at 350 °C. The parameters of the reaction steps were determined and a structural kinetic model was developed. The model was compared with an earlier developed kinetic model for the unpromoted catalyst. It was suggested that an increased reaction selectivity in the presence of silver promoted catalyst was caused by a change in the composition of the adsorption complexes formed by the active sites of the catalyst. This change in the composition of the complexes is probably associated with an increase in the average size of the surface active particles of the catalyst.
Engineering Fatty Acid Photodecarboxylase to Enable Highly Selective Decarboxylation of trans Fatty Acids
Han, Tao,Li, Danyang,Wu, Qi,Xu, Jian,Xu, Weihua,Xue, Jiadan
, p. 20695 - 20699 (2021)
Due to the high risk of heart disease caused by the intake of trans fatty acids, a method to eliminate trans fatty acids from foods has become a critical issue. Herein, we engineered fatty acid photo-decarboxylase from Chlorella variabilis (CvFAP) to selectively catalyze the decarboxylation of trans fatty acids to yield readily-removed hydrocarbons and carbon dioxide, while cis fatty acids remained unchanged. An efficient protein engineering based on FRISM strategy was implemented to intensify the electronic interaction between the residues and the double bond of the substrate that stabilized the binding of elaidic acid in the channel. For the model compounds, oleic acid and elaidic acid, the best mutant, V453E, showed a one-thousand-fold improvement in the trans-over-cis (ToC) selectivity compared with wild type (WT). As the first report of the direct biocatalytic decarboxylation resolution of trans/cis fatty acids, this work offers a safe, facile, and eco-friendly process to eliminate trans fatty acids from edible oils.
The Effect of the Active Component Content on the Catalytic Activity of Nickel Sulfide Catalysts in Olefin Synthesis from Stearic Acid
Katsman,Danyushevsky, V. Ya.,Karpov,Kuznetsov,Shishilov,Berenblyum
, p. 622 - 628 (2019)
Abstract: The effect of active component content on the catalytic activity of supported sulfide catalysts in the synthesis of C17 olefins from stearic acid has been studied. It has been shown that an increase in the nickel content leads to a decrease in the catalyst activity; in addition, there is a negative correlation between the activity and the fraction of large particles on the support surface. The highest heptadecene selectivity (50–60%) is observed for alumina-supported catalysts owing to the higher degree of dispersion of the active component.
Hydrothermal conversion of linoleic acid and ethanol for biofuel production
Besse, Xavier,Schuurman, Yves,Guilhaume, Nolven
, p. 139 - 148 (2016)
The catalytic conversion of linoleic acid in ethanol/water mixtures (1:1 vol. ratio) was explored in a batch reactor using a Pt/C catalyst. Linoleic acid was converted into heptadecane with high yields (>80%) after 6?h at 350?°C under autogenous pressure. The reaction proceeded through consecutive steps: linoleic acid?→?stearic acid?→?ethyl stearate?→?heptadecane. Hydrogen was generated in-situ by oxidation of ethanol into acetaldehyde. A moderate sintering of platinum was evidenced after hydrothermal reaction. A reaction network based on products distribution and kinetic studies was proposed. It was found that the hydrogenation route proceeds via the free acids whereas the hydrogenation of the ethyl esters was negligible. The formation of heptadecane, on the other hand, proceeded via ethyl stearate and not via stearic acid.
Highly stable and selective catalytic deoxygenation of renewable bio-lipids over Ni/CeO2-Al2O3 for N-alkanes
Ba, Wenxia,Cui, Huamin,Fu, Lin,Li, Yongfei,Liu, Yuejin
, (2021/07/31)
Ni-based catalysts are easy deactivated in bio-lipids deoxygenation due to metal aggregation and Ni leaching. They also suffer from the hydrocracking of C–C bonds due to strong acidity at high reaction temperature (≥ 300 ℃). Herein, a series of Ni/CeO2-Al2O3 catalysts with different Ce/Al ratio were prepared by one-pot sol-gel method. The characteristic results showed that an appropriate addition of Ce both increase the catalytic activity and stability in bio-lipids deoxygenation. The oxygen vacancies formed by Ce introduction weaken the strong interaction of Ni-Al, thus improving Ni sites dispersion. Additional, Ce-addition in NiCeAl system increases weak and medium acidity and decreases strong acidity, preventing the C–C bond cleavage of hydrocarbon. As the result, the Ni/CeAl-3.0 catalyst afforded a 97.1 % n-C17 yield at 99.9 % MO conversion under 2.5 MPa H2 at 300 ℃ for 6 h. Minor C15-16 alkanes (17 yield). After simple regeneration, n-C17 yield was recovered to 95 %. Furthermore, non-edible bio-lipids (JO and WCO) can be converted to C13-18 alkanes with 95.2 % and 93.8 % yields, respectively.
A Reconstructed Common Ancestor of the Fatty Acid Photo-decarboxylase Clade Shows Photo-decarboxylation Activity and Increased Thermostability
Sun, Yue,Calderini, Elia,Kourist, Robert
, p. 1833 - 1840 (2021/04/05)
Light-dependent enzymes are a rare type of biocatalyst with high potential for research and biotechnology. A recently discovered fatty acid photo-decarboxylase from Chlorella variabilis NC64A (CvFAP) converts fatty acids to the corresponding hydrocarbons only when irradiated with blue light (400 to 520 nm). To expand the available catalytic diversity for fatty acid decarboxylation, we reconstructed possible ancestral decarboxylases from a set of 12 extant sequences that were classified under the fatty acid decarboxylases clade within the glucose-methanol choline (GMC) oxidoreductase family. One of the resurrected enzymes (ANC1) showed activity in the decarboxylation of fatty acids, showing that the clade indeed contains several photo-decarboxylases. ANC1 has a 15 °C higher melting temperature (Tm) than the extant CvFAP. Its production yielded 12-fold more protein than this wild type decarboxylase, which offers practical advantages for the biochemical investigation of this photoenzyme. Homology modelling revealed amino acid substitutions to more hydrophilic residues at the surface and shorter flexible loops compared to the wild type. Using ancestral sequence reconstruction, we have expanded the existing pool of confirmed fatty acid photo-decarboxylases, providing access to a more robust catalyst for further development via directed evolution.
Light-Driven Enzymatic Decarboxylation of Dicarboxylic Acids
Chen, Bi-Shuang,Liu, Lan,Zeng, Yong-Yi,Zhang, Wuyuan
, p. 553 - 559 (2021/06/25)
Photodecarboxylase from Chlorella variabillis (CvFAP) is one of the three known light-activated enzymes that catalyzes the decarboxylation of fatty acids into the corresponding C1-shortened alkanes. Although the substrate scope of CvFAP has been altered by protein engineering and decoy molecules, it is still limited to mono-fatty acids. Our studies demonstrate for the first time that long chain dicarboxylic acids can be converted by CvFAP. Notably, the conversion of dicarboxylic acids to alkanes still represents a chemically very challenging reaction. Herein, the light-driven enzymatic decarboxylation of dicarboxylic acids to the corresponding (C2-shortened) alkanes using CvFAP is described. A series of dicarboxylic acids is decarboxylated into alkanes in good yields by means of this approach, even for the preparative scales. Reaction pathway studies show that mono-fatty acids are formed as the intermediate products before the final release of C2-shortened alkanes. In addition, the thermostability, storage stability, and recyclability of CvFAP for decarboxylation of dicarboxylic acids are well evaluated. These results represent an advancement over the current state-of-the-art.
