Polymer Magnetically Separable Catalyst for Supercritical Deoxygenation of Fatty Acids

In this paper, the possibility of using a magnetically separated ruthenium-containing catalyst based on a polymer matrix of hypercrosslinked polystyrene in the supercritical deoxygenation of stearic acid to produce a second-generation biodiesel fuel is studied. The catalyst was synthesized by a successive deposition of iron and ruthenium oxides to the polymeric support. The resulting catalytically active Ru-Fe3O4-HPS system is characterized by high specific surface area (364 m2/g) and magnetization (4.5 emu/g). This catalyst allows obtaining a high (up to 86%) yield of hydrocarbons C17+ and exhibits high activity in the process of deoxygenation in supercritical n-hexane. It was found that the selected catalytic system retains its catalytic activity for at least 10 consecutive cycles.

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Magnetically separable Ru-containing catalysts in supercritical deoxygenation of fatty acids

Pure and Applied Chemistry ◽

10.1515/pac-2019-1012 ◽

2020 ◽

Vol 92 (6) ◽

pp. 817-826

Author(s):

Antonina A. Stepacheva ◽

Yury V. Lugovoy ◽

Oleg V. Manaenkov ◽

Alexander I. Sidorov ◽

Valentina G. Matveeva ◽

...

Keyword(s):

Fatty Acids ◽

Magnetic Properties ◽

Catalytic Activity ◽

Magnetic Nanoparticles ◽

Stearic Acid ◽

Ruthenium Oxide ◽

Hypercrosslinked Polystyrene ◽

High Stearic Acid ◽

Magnetically Separable ◽

Effect Of Support

AbstractIn the current paper, the possibility of the use of magnetically separable catalysts containing ruthenium oxide species in the supercritical deoxygenation of stearic acid for producing of the second generation of biodiesel is reported. Three different supports (silica, ceria, and hypercrosslinked polystyrene) were used for the stabilization of magnetic nanoparticles (MNPs) and Ru-containing particles. The effect of support on the magnetic properties as well as the catalytic activity of the obtained systems was studied. All synthesized catalysts were shown to provide high stearic acid conversion (up to 95 %). The highest yield of C17+ hydrocarbons (up to 86 %) was observed while using the Ru–Fe3O4-HPS system. Ru–Fe3O4-HPS was characterized by the high values of the specific surface area (364 m2/g) and saturation magnetization (4.5 emu/g). The chosen catalytic system was found to maintain its catalytic activity for a minimum of 10 consecutive cycles.

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Catalytic Ozonation of 4-Nitrophenol in the Presence of Magnetically Separable Titanium Dioxide – Magnetite Composite

Eurasian Chemico-Technological Journal ◽

10.18321/ectj275 ◽

2016 ◽

Vol 17 (4) ◽

pp. 309 ◽

Cited By ~ 1

Author(s):

D.A. Kazakov ◽

V.V. Vol’khin ◽

K. Kaczmarski ◽

Yu.O. Gulenova ◽

M.N. Obirina ◽

...

Keyword(s):

Catalytic Activity ◽

Active Sites ◽

Fine Particles ◽

Aqueous Media ◽

Composite Catalyst ◽

Hydroxyl Groups ◽

Oh Groups ◽

Catalytically Active ◽

Magnetite Particles ◽

Magnetically Separable

This paper deals with determining catalytic activities of titania (TiO2) with various crystalline structures and magnetite (Fe3O4) during mineralization of 4-nitrophenol in aqueous media by ozonation. Among the titania samples under study, amorphized TiO2 was shown to have the highest catalytic activity, while magnetite was characterized by the lowest catalytic activity. A procedure is proposed to synthesize a magnetically separable composite (TiO2/Fe3O4) including amorphized titania and magnetite phases, which involves deposition of a catalytically active titania phase on preformed magnetite particles. We also studied the effect of mass ratio of titania and magnetite phases in the composite on its catalytic activity during 4-nitrophenol mineralization by ozonation. It was found that catalytic activity of composite increased as the amorphized titania phase was doped with magnetite phase up to 30% wt but as the magnetite portion in the composite catalyst was further increased, its activity decreased. According to Fourier transform infrared (FTIR) spectroscopy, content of catalytically active sites (hydroxyl groups of titania) in the composite catalyst decreases as compared to the pure phase of amorphized titania. Increase in catalytic activity of the composite as its magnetite content increases to 30% wt can be attributed to increase of accessibility of catalytically active sites (OH groups) for ozone, because specific surface area and total pore volume of the composite catalyst as determined by BET increase as compared to amorphized TiO2 and catalytically active titania phase is located mostly on surface of magnetite particles which is indicated by scanning electron microscopy (SEM) results and electrophoretic light scattering (ELS) data. It was shown that the obtained composite catalyst of optimized composition, in spite of its fine particles, can be easily recovered from aqueous phase by magnetic field and used repeatedly in ozonation in order to promote water purification process.

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Hydrogen peroxide decomposition on a two-component CuO-Cr2O3 catalyst

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19881636 ◽

1988 ◽

Vol 53 (8) ◽

pp. 1636-1646 ◽

Cited By ~ 8

Author(s):

Viliam Múčka ◽

Kamil Lang

Keyword(s):

Hydrogen Peroxide ◽

Catalytic Activity ◽

Extreme Values ◽

Catalytic Properties ◽

Active Components ◽

Catalytic Systems ◽

Heterogeneous Catalytic ◽

Peroxide Decomposition ◽

Two Component ◽

Catalytically Active

Some physical and catalytic properties of the two-component copper(II)oxide-chromium(III)oxide catalyst with different content of both components were studied using the decomposition of the aqueous solution of hydrogen peroxide as a testing reaction. It has been found that along to both basic components, the system under study contains also the spinel structure CuCr2O4, chromate washable by water and hexavalent ions of chromium unwashable by water. The soluble chromate is catalytically active. During the first period of the reaction the equilibrium is being established in both homogeneous and heterogeneous catalytic systems. The catalytic activity as well as the specific surface area of the washed solid is a non-monotonous function of its composition. It seems highly probable that the extreme values of both these quantities are not connected with the detected admixtures in the catalytic system. The system under study is very insensitive with regard to the applied doses of gamma radiation. Its catalytic properties are changed rather significantly after the thermal treatment and particularly after the partial reduction to low degree by hydrogen. The observed changes of the catalytic activity of the system under study are very probably in connection with the changes of the valence state of the catalytically active components of the catalyst.

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N-heterocyclic carbene Pd(II) complex supported on Fe3O4@SiO2: Highly active, reusable and magnetically separable catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media

Journal of Organometallic Chemistry ◽

10.1016/j.jorganchem.2021.121823 ◽

2021 ◽

Vol 943 ◽

pp. 121823

Author(s):

Mitat Akkoç ◽

Nesrin Buğday ◽

Serdar Altın ◽

Nadir Kiraz ◽

Sedat Yaşar ◽

...

Keyword(s):

Aqueous Media ◽

Cross Coupling ◽

Coupling Reactions ◽

Cross Coupling Reactions ◽

Highly Active ◽

Magnetically Separable Catalyst ◽

Magnetically Separable

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Bicarbonate for microalgae cultivation: a case study in a chlorophyte, Tetradesmus wisconsinensis isolated from a Norwegian lake

Journal of Applied Phycology ◽

10.1007/s10811-021-02420-4 ◽

2021 ◽

Author(s):

Ikumi Umetani ◽

Eshetu Janka ◽

Michal Sposób ◽

Chris J. Hulatt ◽

Synne Kleiven ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Lipid Production ◽

Cetane Number ◽

Fluorescence Analysis ◽

Dry Weight ◽

Maximum Growth ◽

Biodiesel Fuel ◽

Fatty Acid Production ◽

Total Fatty Acids

AbstractBicarbonate was evaluated as an alternative carbon source for a green microalga, Tetradesmus wisconsinensis, isolated from Lake Norsjø in Norway. Photosynthesis, growth, and lipid production were studied using four inorganic carbon regimes: (1) aeration only, (2) 20 mM NaHCO3, (3) 5% (v/v) CO2 gas, and (4) combination of 20 mM NaHCO3 and 5% CO2. Variable chlorophyll a fluorescence analysis revealed that the bicarbonate treatment supported effective photosynthesis, while the CO2 treatment led to inefficient photosynthetic activity with a PSII maximum quantum yield as low as 0.31. Conversely, bicarbonate and CO2 treatments gave similar biomass and fatty acid production. The maximum growth rate, the final cell dry weight, and total fatty acids under the bicarbonate-only treatment were 0.33 (± 0.06) day−1, 673 (± 124) mg L−1 and 75 (± 5) mg g−1 dry biomass, respectively. The most abundant fatty acid components were α-linolenic acid and polyunsaturated fatty acids constituting 69% of the total fatty acids. The fatty acid profile eventuated in unsuitable biodiesel fuel properties such as high degree of unsaturation and low cetane number; however, it would be relevant for food and feed applications. We concluded that bicarbonate could give healthy growth and comparative product yields as CO2.

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Role of CO2 During Oxidative Dehydrogenation of Propane Over Bulk and Activated-Carbon Supported Cerium and Vanadium Based Catalysts

Catalysis Letters ◽

10.1007/s10562-020-03519-y ◽

2021 ◽

Author(s):

Petar Djinović ◽

Janez Zavašnik ◽

Janvit Teržan ◽

Ivan Jerman

Keyword(s):

Catalytic Activity ◽

Activated Carbon ◽

Oxidative Dehydrogenation ◽

Active Phase ◽

Lattice Oxygen ◽

Chemisorbed Oxygen ◽

Catalytically Active ◽

Temperature Programmed ◽

Propane Cracking

AbstractCeO2, V2O5 and CeVO4 were synthesised as bulk oxides, or deposited over activated carbon, characterized by XRD, HRTEM, CO2-TPO, C3H8-TPR, DRIFTS and Raman techniques and tested in propane oxidative dehydrogenation using CO2. Complete oxidation of propane to CO and CO2 is favoured by lattice oxygen of CeO2. The temperature programmed experiments show the ~ 4 nm AC supported CeO2 crystallites become more susceptible to reduction by propane, but less prone to re-oxidation with CO2 compared to bulk CeO2. Catalytic activity of CeVO4/AC catalysts requires a 1–2 nm amorphous CeVO4 layer. During reaction, the amorphous CeVO4 layer crystallises and several atomic layers of carbon cover the CeVO4 surface, resulting in deactivation. During reaction, V2O5 is irreversibly reduced to V2O3. The lattice oxygen in bulk V2O5 favours catalytic activity and propene selectivity. Bulk V2O3 promotes only propane cracking with no propene selectivity. In VOx/AC materials, vanadium carbide is the catalytically active phase. Propane dehydrogenation over VC proceeds via chemisorbed oxygen species originating from the dissociated CO2. Graphic Abstract

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From Ru nanoparticle-encapsulated metal–organic frameworks to highly catalytically active Cu/Ru nanoparticle-embedded porous carbon

Journal of Materials Chemistry A ◽

10.1039/c6ta10748f ◽

2017 ◽

Vol 5 (10) ◽

pp. 4835-4841 ◽

Cited By ~ 54

Author(s):

Pradip Pachfule ◽

Xinchun Yang ◽

Qi-Long Zhu ◽

Nobuko Tsumori ◽

Takeyuki Uchida ◽

...

Keyword(s):

Catalytic Activity ◽

High Temperature ◽

Porous Carbon ◽

Metal Organic Frameworks ◽

Ammonia Borane ◽

Carbon Composites ◽

High Catalytic Activity ◽

Catalytically Active ◽

Metal Organic

High-temperature pyrolysis of Ru nanoparticle-encapsulated MOF (Ru@HKUST-1) afforded ultrafine Cu/Ru nanoparticle-embedded porous carbon composites (Cu/Ru@C), which show high catalytic activity for ammonia borane hydrolysis.

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