SOURCES OF HYDROGEN DONORS AND THEIR EFFECTS ON DENITRIFICATION RATES

AbstractHydrotreatment of bio-oil oxygen compounds allows the final product to be effectively used as a liquid transportation fuel from biomass. Deoxygenation is considered to be one of the most promising ways for bio-oil upgrading. In the current work, we describe a novel approach for the deoxygenation of bio-oil model compounds (anisole, guaiacol) using supercritical fluids as both the solvent and hydrogen-donors. We estimated the possibility of the use of complex solvent consisting of non-polar n-hexane with low critical points (Tc = 234.5 ºC, Pc = 3.02 MPa) and propanol-2 used as H-donor. The experiments were performed without catalysts and in the presence of noble and transition metals hydrothermally deposited on the polymeric matrix of hypercrosslinked polystyrene (HPS). The experiments showed that the presence of 20 vol. % of propanol-2 in n-hexane results in the highest (up to 99%) conversion of model compounds. When the process was carried out without a catalyst, phenols were found to be a major product yielding up to 95 %. The use of Pd- and Co-containing catalyst yielded 90 % of aromatic compounds (benzene and toluene) while in the presence of Ru and Ni cyclohexane and methylcyclohexane (up to 98 %) were the main products.

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DELAYED-LIGHT STUDIES ON PHOTOSYNTHETIC ENERGY CONVERSION-IV. EFFECT OF TRIS POISONING, AND OF ITS REVERSAL BY HYDROGEN DONORS, ON THE MILLISECOND EMISSION FROM CHLOROPLASTS*

Photochemistry and Photobiology ◽

10.1111/j.1751-1097.1971.tb06171.x ◽

1971 ◽

Vol 14 (3) ◽

pp. 251-260 ◽

Cited By ~ 14

Author(s):

W. BERTSCH ◽

SUSAN LURIE

Keyword(s):

Energy Conversion ◽

Hydrogen Donors

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2-Aryl-1,3-dimethylbenzimidazolines as Effective Electron and Hydrogen Donors in Photoinduced Electron-Transfer Reactions

Australian Journal of Chemistry ◽

10.1071/ch15314 ◽

2015 ◽

Vol 68 (11) ◽

pp. 1640 ◽

Cited By ~ 11

Author(s):

Eietsu Hasegawa ◽

Shin-ya Takizawa

Keyword(s):

Electron Transfer ◽

Hydrogen Atom ◽

Photoinduced Electron Transfer ◽

Hydrogen Atom Transfer ◽

Transfer Reactions ◽

Organic Substrates ◽

Iridium Complexes ◽

Effective Electron ◽

Hydrogen Donors ◽

Wavelength Light

2-Aryl-1,3-dimethylbenzimidazolines (DMBIHs) have been applied to photoinduced electron-transfer reductions of various organic substrates. Either direct or indirect electron transfer between the substrates and DMBIHs is utilized to promote the desired transformations. Photoexcitation of the substrates using light above 280 nm was carried out in the former protocol whereas a photosensitization method using materials such as substituted pyrenes, ruthenium and iridium complexes that absorb longer-wavelength light was employed in the latter. In these reactions, DMBIHs undergo initial electron transfer and subsequent proton or hydrogen atom transfer.

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Oxygen, Hydrogen Donors and Radiation Response

Advances in Experimental Medicine and Biology - Hyperthermia ◽

10.1007/978-1-4684-4388-2_14 ◽

1982 ◽

pp. 147-175 ◽

Cited By ~ 3

Author(s):

John E. Biaglow

Keyword(s):

Radiation Response ◽

Hydrogen Donors

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Hydrogen Transfer Reactions of Carbonyls, Alkynes, and Alkenes with Noble Metals in the Presence of Alcohols/Ethers and Amines as Hydrogen Donors

Catalysts ◽

10.3390/catal8120671 ◽

2018 ◽

Vol 8 (12) ◽

pp. 671 ◽

Cited By ~ 11

Author(s):

Eszter Baráth

Keyword(s):

Condensed Phase ◽

Crucial Role ◽

Noble Metals ◽

Hydrogen Transfer ◽

Transfer Reactions ◽

Hydrogen Donors ◽

Stereoselective Reactions ◽

Present Summary ◽

Industrial Relevance ◽

Hydrogen Transfer Reactions

Hydrogen transfer reactions have exceptional importance, due to their applicability in numerous synthetic pathways, with academic as well as industrial relevance. The most important transformations are, e.g., reduction, ring-closing, stereoselective reactions, and the synthesis of heterocycles. The present review provides insights into the hydrogen transfer reactions in the condensed phase in the presence of noble metals (Rh, Ru, Pd) as catalysts. Since the H-donor molecules (such as alcohols/ethers and amines (1°, 2°, 3°)) and the acceptor molecules (alkenes (C=C), alkynes (C≡C), and carbonyl (C=O) compounds) play a crucial role from mechanistic viewpoints, the present summary points out the key mechanistic differences with the interpretation of current contributions and the corresponding historical achievements as well.

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