Results 261 to 270 of about 65,032 (285)

Selective hydrogenation and transfer hydrogenation reactions

2018
Diese Dissertation beschreibt Untersuchungen an Katalysatoren zur selektiven Transferhydrierung von ungesättigten Carbonylverbindungen. Insbesondere wird die Anwendbarkeit von EtOH als alternative Wasserstoffquelle zu dem weitverbreiteten iPOH beschrieben und diskutiert.
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Selective hydrogenation over ruthenium catalysts

Applied Catalysis A: General, 1995
Ruthenium catalysts are widely used for selective hydrogenation of a carbonyl group in the vicinity of conjugated or isolated double bonds. The α,β-unsaturated alcohols prepared in this way are compounds of great commercial importance. The effects of promoters, particle size and supports on such reactions are discussed.
Petr Kluson, Libor Cerveny
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Selective catalytic hydrogenation of acetylenes

Tetrahedron, 1961
Abstract The products of the stepwise catalytic hydrogenation of undeca-1,7-diyne (I) have been examined and the sequence of the reduction established. The ethynyl group may be protected during catalytic hydrogenation by conversion into the corresponding 1-bromoacetylene.
N.A. Dobson, G. Eglinton, M. Krishnamurti, R.A. Raphael, R.G. Willis   +4 more
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Selective Oxidation of Hydrogen to Hydrogen Peroxide

1992
Abstract The synthesis of hydrogen peroxide (H 2 O 2 ) using H 2 ‐O 2 was studied at temperatures from -10°C to 25°C and pressures from 0.50 MPa to 2.3 MPa. Active catalysts included platinum group metals attached to hydrophobic carbon, supported on a mixture of hydrophobic and hydrophilic materials.
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Hydrogen-selective thermoelectric gas sensor

Sensors and Actuators B: Chemical, 2003
Abstract A thermoelectric (TE) hydrogen gas sensor was fabricated by depositing a platinum catalyst thin film on the half surface of nickel oxide thick film. When it was exposed to combustible gas diluted by synthetic air, the catalyst layer converts hydrogen and oxygen effectively to water vapor, and give out heat energy, resulting temperature ...
Woosuck Shin, Masahiko Matsumiya, Noriya Izu, Norimitsu Murayama   +3 more
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A Selective Iron(I) Hydrogenation Catalyst

Journal of the American Chemical Society
Iron is the most abundant transition metal of the Earth's crust, and the understanding of its function in key technologies, such as catalysis, is highly important. We report here on an iron(I) hydrogenation catalyst. Our catalyst activates hydrogen via heterolytic bond cleavage, forms a monohydride, and hydrogenates polar double bonds via a bimetallic ...
Niko Sila, Andreas Dürrmann, Birgit Weber, Frank W. Heinemann, Torsten Irrgang, Rhett Kempe   +5 more
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Selective adsorption and hydrogen embrittlement

Metallurgical Transactions A, 1976
This paper presents a definite correlation between hydrogen embrittlement and adsorption. The effects of the presence of gaseous additives on hydrogen embrittlement and hydrogen adsorption were studied. Those gaseous additives which halt a running crack in 4340 steel loaded in a hydrogen atmosphere also halt hydrogen adsorption. Those gaseous additives
V. Srikrishnan, P. J. Ficalora
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Tungsten–palladium selective hydrogenation catalysts

Catalysis Letters, 1998
The activity and sulfur resistance of palladium–tungsten supported catalysts having different W/Pd ratios is compared. The maximum was found for the catalyst having a W/Pd ratio 6. The existence of a Pd–WOx interface, more active and sulfur‐resistant, is suggested. Regeneration of bimetallic catalysts at mild temperatures was studied.
P.C. L’Argentière, N.S. Fígoli
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Selective Antioxidative Effect of Hydrogen

2015
Selective antioxidation is the mechanism underlying the biological effect of hydrogen, which has been widely recognized. We cannot fully understand this mechanism until we are familiar with radicals, reactive oxygen species, and oxidative damage. In order to let the readers have a general understanding of free radical biology, this chapter provides ...
Qiang Sun, Wenjie Han, Atsunori Nakao
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Hydrogen-selective silica based membrane [PDF]

, 2016
A new type of silica-modified membrane has been developed by the high-temperature, atmospheric-pressure CVD of Vycor glass. The new membrane, Nanosil, showed unprecedented selectivity to hydrogen (100%), without loss of permeability compared to the porous Vycor precursor.
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