The hydrogenation of allene. III. The reaction of allene with hydrogen catalyzed by nickel, copper, and their alloys

1970 ◽  
Vol 48 (21) ◽  
pp. 3324-3331 ◽  
Author(s):  
R. S. Mann ◽  
A. M. Shah
Keyword(s):  
Copper Content ◽  
Activation Energies ◽  
Constant Volume ◽  
Early Stages ◽  
Nickel Copper ◽  
Selective Formation

The reaction between allene and hydrogen over unsupported nickel, copper, and their alloys has been investigated in a static constant volume system between 26 and 131 °C for a wide reactant ratios. The orders of reaction with respect to hydrogen and allene were one and zero, respectively, and temperature independent. The reaction over metals and their alloys is largely simple hydrogenation, the early stages being principally a selective formation of propylene, with small yields of reduced polymers of allene. The overall activation energies varied between 4.8 and 11.8 kcal/g-mole. Selectivity was highest with copper and least with nickel. The amount of allene polymerized was not related in any particular way to the copper content of alloy.

The hydrogenation of allene. II. The reaction of allene with hydrogen catalyzed by nickel, cobalt, and iron

1968 ◽  
Vol 46 (20) ◽  
pp. 3249-3254 ◽  
Author(s):  
R. S. Mann ◽  
D. E. Tiu
Keyword(s):  
Activation Energies ◽  
Constant Volume ◽  
Cobalt Catalysts ◽  
Kcal Mole ◽  
Nickel Iron ◽  
Early Stages ◽  
Nickel Cobalt ◽  
Wide Range ◽  
Apparent Activation Energies ◽  
Selective Formation

The reaction between allene and hydrogen over unsupported nickel, iron, and cobalt catalysts has been studied in a static constant volume system for a wide range of temperature and reactant ratios. The reaction over metals is largely simple hydrogenation, the early stages being principally a selective formation of propylene with small yields of reduced polymers of allene. The orders of the hydrogenation were 1 and 0 with respect to hydrogen and allene respectively, and were temperature independent. The overall apparent activation energies for nickel, iron, and cobalt were 6.5, 7.6, and 6.9 kcal/mole respectively. Selectivity was highest with nickel, and least with cobalt.

scholarly journals Catalytic hydrogenation of allene

1968 ◽  
Vol 46 (2) ◽  
pp. 161-166 ◽  
Author(s):  
R. S. Mann ◽  
D. E. To
Keyword(s):  
Catalytic Hydrogenation ◽  
Hydrogenation Reaction ◽  
Activation Energies ◽  
Constant Volume ◽  
Kcal Mole ◽  
Catalytic Activities ◽  
Pressure Time ◽  
Wide Range ◽  
Apparent Activation Energies ◽  
Selective Formation

The reaction between allene and hydrogen over pumice-supported metals of the eighth group has been investigated in a constant volume reactor for a wide range of temperature and reactant ratios. The shape of the pressure–time curves were found to be dependent upon the reactant ratios and their order of admission. The reaction over nickel–pumice is principally a selective formation of propylene with small yields of propane and reduced polymers of allene. The orders of hydrogenation reaction are first, or slightly higher, and zero with respect to hydrogen and allene respectively. The apparent activation energies for Pd, Pt, Co, Fe, Ni, Rh, Ir, Ru, and Os are 13, 17.4, 10.8, 9.4, 7.8, 9.6, 5.3, 3.0, and 4.6 kcal/mole respectively. The catalytic activities of the metals are in the sequence[Formula: see text]While selectivity was found to decrease with increasing initial hydrogen pressures, it increased with increasing temperatures.

The hydrogenation of methylacetylene. II. The reaction of methylacetylene with hydrogen catalyzed by nickel, iron, and cobalt

1967 ◽  
Vol 45 (22) ◽  
pp. 2755-2760 ◽  
Author(s):  
R. S. Mann ◽  
K. C. Khulbe
Keyword(s):  
Cobalt Catalyst ◽  
Activation Energies ◽  
Constant Volume ◽  
Kcal Mole ◽  
Nickel Iron ◽  
Early Stages ◽  
Wide Range ◽  
Apparent Activation Energies

The reaction between methylacetylene and hydrogen over unsupported nickel, iron, and cobalt catalyst has been investigated in a static constant volume system for a wide range of temperature and reactant ratios. The reaction over metals is largely simple hydrogenation, the early stages being principally a selective production of propylene with small yields of reduced polymers of methylacetylene. The orders of the hydrogenation were first and zero to slightly negative with respect to hydrogen and methylacetylene. The overall apparent activation energies for nickel, iron, and cobalt were 12.2, 8.1, and 7.3 kcal/mole respectively. Selectivity was highest with iron and least with nickel.

Hydrogenation of methylacetylene. III. The reaction of methylacetylene with hydrogen catalyzed by nickel, copper, and their alloys

1968 ◽  
Vol 46 (4) ◽  
pp. 623-633 ◽  
Author(s):  
R. S. Mann ◽  
K. C. Khulbe
Keyword(s):  
Activation Energy ◽  
Nickel Catalyst ◽  
Hydrogen Pressure ◽  
Constant Volume ◽  
Temperature Dependent ◽  
Nickel Copper ◽  
Wide Range ◽  
Initial Hydrogen Pressure

The reaction between methylacetylene and hydrogen over unsupported nickel, copper, and their alloys has been investigated in a static constant volume system between 20 and 220 °C for a wide range of reactant ratios. The order of reaction with respect to hydrogen was one and nearly independent of temperature. While the order of reaction with respect to methylacetylene over nickel catalyst was slightly negative and temperature dependent, it was always positive and nearly independent of temperature for copper and copper-rich alloys. Selectivity was independent of initial hydrogen pressure for nickel and copper only; for others it decreased rapidly with increasing hydrogen pressure. The overall activation energy varied between 9 and 21.2 kcal/g mole. Selectivity and extent of polymerization increased with increasing amount of copper in the alloy.

The Hydrogenation of Allene. IV. The Reaction of Allene with Hydrogen Catalyzed by Palladium, Platinum, Iridium, Rhodium, Ruthenium, and Osmium Catalysts

1972 ◽  
Vol 50 (12) ◽  
pp. 1793-1796 ◽  
Author(s):  
R. S. Mann ◽  
A. M. Shah
Keyword(s):  
Activation Energies ◽  
Constant Volume ◽  
Catalytic Activities ◽  
Wide Range ◽  
Apparent Activation Energies ◽  
Palladium Platinum

The reaction between allene and hydrogen over unsupported palladium, platinum, iridium, rhodium, ruthenium, and osmium catalysts has been investigated in a static constant volume system between 70 and 149 °C for a wide range of reactant ratios. The orders of reaction with respect to hydrogen and allene were one and zero, respectively, and temperature independent. The overall apparent activation energies for unsupported platinum, iridium, palladium and rhodium were 17.7, 9.1, 6.4, and 17.4 kcal/mol, respectively. The catalytic activities of the unsupported metals were in the sequence Pd > Ir > Rh > Pt > Ru, Os. Selectivity was highest with palladium and rhodium, and least with iridium. The polymerization was highest with platinum and least with indium.

Multilayer Nickel–Copper Anode for Direct Glucose Fuel Cell

2019 ◽  
Vol 16 (4) ◽  
Author(s):  
Antonina Maizelis
Keyword(s):  
Surface Area ◽  
Copper Content ◽  
Copper Ions ◽  
Multilayer Coating ◽  
Real Surface ◽  
Nickel Ions ◽  
Copper Coatings ◽  
Nickel Copper ◽  
Direct Glucose Fuel Cell ◽  
Glucose Oxidation Reaction

Multilayer nickel–copper coatings consisting of layers of nickel–copper alloy and a mixture of metals with hydroxides were obtained by electrodeposition from polyligand pyrophosphate–ammonia electrolyte by the two-pulse potentiostatic method. A comparison between two different electrodes with the same real surface area is presented. The equality of the surface area of electrodes deposited from the electrolyte containing different copper and nickel ions’ concentration ratio was achieved by deposition of different numbers of layers. It is shown that the increase in the copper content in electrolyte leads to an increase in the copper ions’ content in the coating and the electrode surface develops more intensively. Freshly deposited coatings have approximately the same catalytic activity in the glucose oxidation reaction in the alkaline solution. But a multilayer coating with a higher copper content is more corrosion resistant and more stable in long-term electrolysis.

SIMULTANEOUS DETERMINATIONS OF TRACE ELEMENTS IN SERA OF PATIENTS WITH ACUTE MYOCARDIAL INFARCTION BY PIXE

1993 ◽  
Vol 03 (04) ◽  
pp. 295-300 ◽  
Author(s):  
Y. MIURA ◽  
C. ITOH ◽  
T. MIYAKAWA ◽  
K. NAKAI ◽  
K. HIRAMORI ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Copper Content ◽  
Healthy Controls ◽  
Control Subjects ◽  
Nickel Copper ◽  
Significant Difference ◽  
Iron Nickel ◽  
Copper Zinc ◽  
Zinc Nickel

Using PIXE we determined concentrations of iron, nickel, copper, zinc, selenium, and rubidium in sera of 24 patients with acute myocardial infarction and 12 healthy controls. Rubidium*, selenium*, zinc**, nickel** and iron** concentrations are significantly (P<0.001*, P<0.01**) lower for patients than for control subjects. No significant difference is observed in the copper content. However, there is a slight increase in copper content in the patients so that the ratios Cu/Rb, Cu/Se, Cu/Zn, Cu/Ni, Cu/Fe are significantly higher for the patients than for the control subjects (P<0.01).

Sintering Behavior of Ba2CaWO6-Doped-Tungsten

1993 ◽  
Vol 322 ◽  
Author(s):  
J.A. Ruud ◽  
B.P. Bewlay
Keyword(s):  
Grain Boundary ◽  
Mass Loss ◽  
Boundary Diffusion ◽  
Activation Energies ◽  
Grain Boundary Diffusion ◽  
Sintering Behavior ◽  
Densification Mechanism ◽  
Early Stages ◽  
Kinetics Of

AbstractThe sintering behavior of Ba2CaWO6 co-sintered with W powder was investigated. Measurements of density and mass loss of sintered compacts showed that the Ba2CaWO6-doped-W had a lower density than undoped W and that there was little volatilization of Ba2CaWO6 at temperatures below 1750 °C. The activation energies for densification of Ba2CaWO6-doped-W and undoped W were both measured to be 389 kJ/mol, which indicates the same densification mechanism, grain boundary diffusion, operated for both materials. The reduced densification kinetics of the Ba2CaWO6-doped-W was probably due to increased coarsening in the early stages of sintering.

Electrical conduction in the phthalocyanines. I. Optical properties

1964 ◽  
Vol 17 (7) ◽  
pp. 750 ◽  
Author(s):  
PE Fielding ◽  
AG MacKay
Keyword(s):  
Optical Properties ◽  
Organic Semiconductors ◽  
Electrical Conduction ◽  
Activation Energies ◽  
Optical Data ◽  
Published Data ◽  
Metal Free ◽  
Data Comparison ◽  
Nickel Copper ◽  
Copper Zinc

The polarized crystal and vapour spectra of metal-free, nickel, copper, zinc, chromium, cobalt, and iron phthalocyanines are reported and the results compared with published data. Comparison between these optical data and activation energies for dark conduction raises doubts as to the ability of the "singlet" or "triplet" theories to explain satisfactorily electrical conduction in organic semiconductors.

Spherulitic crystal growth in the prodissoconch larval of Crassostrea virginica

1983 ◽  
Vol 41 ◽  
pp. 518-519
Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee
Keyword(s):  
Crystal Structure ◽  
Crassostrea Virginica ◽  
Crystal Orientation ◽  
Developmental Changes ◽  
Gastrula Stage ◽  
Orthorhombic Crystal ◽  
Orthorhombic Crystal Structure ◽  
Stages Of Growth ◽  
Early Stages ◽  
Initial Deposition

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.

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