544-76-3Relevant articles and documents
Conversion of palmitic acid to jet fuel components over Mo/H-ZSM-22 bi-functional catalysts with high carbon reservation
Cao, Hongbin,Shi, Yanchun,Wu, Yulong,Yang, Mingde,Zhang, Jimei
, (2020)
The optimal preparation conditions of Mo/H-ZSM-22 bi-functional catalysts were obtained via the sublimation phenomenon of MoO3 at high calcination temperatures, which was beneficial for the well-dispersion of MoOx species with 5?10 nm particles. High reduction temperature enhanced the reduction from Mo6+ to Mo4+ and even from Mo4+ to Mo°, which would be beneficial for iso-alkanes formation with higher carbon reservation. Importantly, 89.3 % selectivity of C16 alkanes of which 61.7 % were iso-C16 alkanes were obtained with complete deoxygenation of palmitic acid, which was the highest selectivity of C16 alkanes over Mo/H-ZSM-22 bi-functional catalyst prepared at a calcination temperature of 550 °C and at a reduction temperature of 600 °C. The results would offer a novel candidate of bi-functional catalysts for upgrading of microalgae-based bio-oil to high-value jet fuel components with high selectivity of iso-alkanes and carbon reservation.
Synthesis of bulk and supported nickel phosphide using microwave radiation for hydrodeoxygenation of methyl palmitate
Xue, Yinan,Guan, Qingxin,Li, Wei
, p. 53623 - 53628 (2015)
In this paper, we proposed a novel method for preparing bulk and supported Ni2P catalysts under mild conditions. Ni2P and Ni2P/SiO2 were synthesized from nickel hypophosphite precursors at 230 °C for 5 min using a CEM Discover microwave reactor, and the initial reaction temperature is about 202 °C. The catalysts were characterized using XRD, TEM, SEM, XPS, BET, carbon monoxide chemisorption, and the catalytic performance was tested for hydrodeoxygenation (HDO) of methyl palmitate in a fixed-bed reactor. Interestingly, microwave irradiation does not result in sintering of Ni2P particles. The principal products of the HDO reaction for both catalysts are pentadecane and hexadecane. Isomerization products were not detected, and other by-products content is very low (1%). The HDO results demonstrate that the catalyst prepared using a microwave has better activity than that prepared using calcination.
Decarboxylation of fatty acids over Pd supported on mesoporous carbon
Simakova, Irina,Simakova, Olga,M?ki-Arvela, P?ivi,Murzin, Dmitry Yu.
, p. 28 - 31 (2010)
Fatty acid decarboxylation was studied in a semibatch reactor over 1 wt.% Pd/C (Sibunit) using five different fatty acids, C17-C20 and C22, as feeds. The same decarboxylation rates were obtained for pure fatty acids, whereas extensive catalyst poisoning and/or sintering and coking occurred with low purity fatty acids as reactants. One reason for catalyst poisoning using behenic acid (C22) as a feedstock was its high phosphorus content. The decarboxylation rate of fatty acids decreased also with increasing fatty acid to metal ratio.
Catalytic performance and deoxygenation path of methyl palmitate on Ni2P/SiO2 synthesized using the thermal decomposition of nickel hypophosphite
Guan, Qingxin,Han, Fei,Li, Wei
, p. 31308 - 31315 (2016)
In this paper, the catalytic performance and deoxygenation path of methyl palmitate on Ni2P/SiO2 catalysts were systematically studied in a continuous flow fixed-bed reactor. A series of Ni2P/SiO2 catalysts (with different molar ratios of P/Ni and Ni2P loadings) were synthesized at 300°C using the thermal decomposition of nickel hypophosphite. The increased molar ratio of P/Ni generates phosphate-rich nickel phosphide catalysts and increasing conversion. Interestingly, Ni2P/SiO2 showed significantly higher conversion of methyl palmitate in comparison with Ni/SiO2. Furthermore, an activation temperature higher than 500°C would significantly reduce the catalytic activity, as a result of the sintering of Ni2P. The pressure in a range of 3.0 to 0.5 MPa almost has no effect on the deoxygenation of methyl palmitate, but significantly affects the reaction path and product distribution. Finally, a possible deoxygenation path over Ni2P/SiO2 was proposed based on a GC-MS investigation.
Linear long-chain α-olefins from hydrodeoxygenation of methyl palmitate over copper phyllosilicate catalysts
Choojun, Kittisak,Huang, Ai-Lin,Lin, Yu-Chuan,Poo-arporn, Yingyot,Prasanseang, Warot,Sooknoi, Tawan
, (2022/03/01)
Copper phyllosilicate (CuPS) was used as a bifunctional catalyst for hydrodeoxygenation of methyl palmitate (MP) to produce long-chain α-olefins without the loss of carbon backbone. The CuPS catalysts were prepared by ammonia evaporation-hydrothermal method. The crystal structure, surface area, reducibility, Cu dispersion, Cu particle size and acidity of the catalysts were examined by XRD, BET, H2-TPR, TEM, NH3-TPD and Py-IR. The existence of Cu2+ species (octahedral (Oh)/square planar (Sq)), Cu+ and Cu0 upon calcination/reduction was investigated by in situ TR-XANES. The Cu dispersion was related to the Cu+ fraction in CuPS, while Br?nsted acid sites (BAS) depends on Cu0 particles. The MP conversion to 1-hexadecene proceeds via hydrogenation-dehydration promoted by the synergy of Cu0 surface and Br?nsted acid sites at the interface. The α-olefin selectivity depends on a balance between Cu+ and Cu loading. The 20CuPS possessing 10% Cu+ fraction, provides a high conversion of 72% with 45% α-olefin selectivity.
Cobalt Complexes of Bulky PNP Ligand: H2Activation and Catalytic Two-Electron Reactivity in Hydrogenation of Alkenes and Alkynes
Fayzullin, Robert R.,Gallagher, James M.,Khaskin, Eugene,Khusnutdinova, Julia R.,Lapointe, Sébastien,Osborne, James,Pandey, Dilip K.
supporting information, p. 3617 - 3626 (2021/11/16)
The reactivity of cobalt pincer complexes supported by the bulky tetramethylated PNP ligands Me4PNPR(R = iPr, tBu) has been investigated. In these ligands, the undesired H atom loss reactivity observed earlier in some classical CH2-arm PNP cobalt complexes is blocked, allowing them to be utilized for promoting two-electron catalytic transformations at the cobalt center. Accordingly, reaction of the formally CoIMe complex 3 with H2 under ambient pressure and temperature afforded the CoIII trihydride 4-H, in a reaction cascade reasoned to proceed by two-electron oxidative addition and reductive eliminations. This mechanistic proposal, alongside the observance of alkene insertion and ethane production upon sequential exposure of 3 to ethylene and H2, prompted an exploration into 3 as a catalyst for hydrogenation. Complex 4-H, formed in situ from 3 under H2, was found to be active in the catalytic hydrogenation of alkenes and alkynes. The proposed two-electron mechanism is reminiscent of the platinum group metals and demonstrates the utility of the bulky redox-innocent Me4PNPR ligand in the avoidance of one-electron reactivity, a concept that may show broad applicability in expanding the scope of earth-abundant first-row transition-metal catalysis.
Highly active cobalt complex catalysts used for alkene hydrosilylation
Liu, Yu,Li, Jiayun,Bai, Ying,Peng, Jiajian
, (2021/07/02)
A series of nitrogen phosphine ligands were synthesized, and the hydrosilylation reaction of alkenes catalyzed using MCl2 in the presence of these ligands was investigated. FeCl2/1(N1, N1, N2, N2-Tetrakis[(diphenylphosphino)methyl]ethane-1,2-diamine) showed low catalytic activity. MnCl2/1, CrCl3/1 and NiCl2/1 showed some catalytic activity. The CoCl2/N,P-ligand catalyst system showed high activity as well as excellent selectivity (The selectivity of the β-adduct was ~100%.) in the hydrosilylation reaction. CoCl2/1 showed the highest catalytic activity (~ >99.9% conversion of 1-octene). Additionally, no α-adduct, dehydrogenative silylation product and octane were detected.
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.
Synthesis and Reactivity of (N2P2)Ni Complexes Stabilized by a Diphosphonite Pyridinophane Ligand
Fuchigami, Kei,Watson, Michael B.,Tran, Giang N.,Rath, Nigam P.,Mirica, Liviu M.
supporting information, p. 2283 - 2289 (2021/05/06)
A series of (N2P2)NiIIcomplexes (N2P2 =P,P′-ditertbutyl-2,11-diphosphonito[3.3](2,6)pyridinophane) stabilized by a modified tetradentate pyridinophane ligand containing two phosphonite groups were synthesized and characterized. Cyclic voltammetry (CV) studies revealed the accessibility of the NiIoxidation state at moderate redox potentials for these NiIIcomplexes.In situEPR, low-temperature UV-vis, and electrochemical studies were employed to detect the formation of NiIspecies during the reduction of NiIIprecursors. Furthermore, the [(N2P2)NiI(CNt-Bu)](SbF6) complex was isolated upon reduction of the NiIIprecursor with 1 equiv of CoCp2and was characterized by EPR and X-ray photoelectron spectroscopy (XPS). Finally, the (N2P2)NiIIBr2complex acts as an efficient catalyst for the Kumada cross-coupling of an aryl halide with an aryl or alkyl Grignard, suggesting that the N2P2 ligand can support the various Ni species involved in the catalytic C-C bond formation reactivity.
Low-Temperature Hypergolic Ignition of 1-Octene with Low Ignition Delay Time
Sheng, Haoqiang,Huang, Xiaobin,Chen, Zhijia,Zhao, Zhengchuang,Liu, Hong
, p. 423 - 434 (2021/02/05)
The attainment of the efficient ignition of traditional liquid hydrocarbons of scramjet combustors at low flight Mach numbers is a challenging task. In this study, a novel chemical strategy to improve the reliable ignition and efficient combustion of hydrocarbon fuels was proposed. A directional hydroboration reaction was used to convert hydrocarbon fuel into highly active alkylborane, thereby leading to changes in the combustion reaction pathway of hydrocarbon fuel. A directional reaction to achieve the hypergolic ignition of 1-octene was designed and developed by using Gaussian simulation. Borane dimethyl sulfide (BDMS), a high-energy additive, was allowed to react spontaneously with 1-octene to achieve the hypergolic ignition of liquid hydrocarbon fuel at -15 °C. Compared with the ignition delay time of pure 1-octene (565 °C), the ignition delay time of 1-octene/BDMS (9:1.2) decreased by 3850% at 50 °C. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry confirmed the directional reaction of the hypergolic ignition reaction pathway of 1-octene and BDMS. Moreover, optical measurements showed the development trend of hydroxyl radicals (OH·) in the lower temperature hypergolic ignition and combustion of 1-octene. Finally, this study indicates that the enhancement of the low-temperature ignition performance of 1-octene by hydroboration in the presence of BDMS is feasible and promising for jet propellant design with tremendous future applications.
