Supercritical Fluid Deposition of Ruthenium Thin Films: A Kinetic Study

2007 ◽  
Vol 992 ◽  
Author(s):  
Christos F. Karanikas ◽  
James J. Watkins
Keyword(s):  
Thin Films ◽  
Growth Rate ◽  
Deposition Temperature ◽  
Zero Order ◽  
Measurable Effect ◽  
Deposition Rates ◽  
Reaction Pressure ◽  
Deposition Kinetics ◽  
First Order ◽  
Kinetics Of

AbstractThe kinetics of the deposition of ruthenium thin films from the hydrogen assisted reduction of bis(2,2,6,6-tetramethyl-3,5-heptanedionato)(1,5-cyclooctadiene)ruthenium(II), [Ru(tmhd)2cod], in supercritical carbon dioxide was studied in order to develop a rate expression for the growth rate as well as to determine a mechanism for the process. The deposition temperature was varied from 240°C to 280°C and the apparent activation energy was 45.3 kJ/mol. Deposition rates up to 30 nm/min were attained. The deposition rate dependence on precursor concentrations between 0 and 0.2 wt. % was studied at 260°C with excess hydrogen and revealed first order deposition kinetics with respect to precursor at concentrations lower then 0.06 wt. % and zero order dependence at concentrations above 0.06 wt. %. The effect of reaction pressure on the growth rate was studied at a constant reaction temperature of 260°C and pressures between 159 bar to 200 bar and found to have no measurable effect on the growth rate.

Kinetics of catalytic reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst

1983 ◽  
Vol 48 (11) ◽  
pp. 3202-3208 ◽  
Author(s):  
Zdeněk Musil ◽  
Vladimír Pour
Keyword(s):  
Carbon Monoxide ◽  
Nitrogen Oxide ◽  
Rate Equation ◽  
Catalytic Reduction ◽  
Zero Order ◽  
Spectroscopic Measurements ◽  
First Order ◽  
Ir Spectroscopic ◽  
Kinetics Of ◽  
Al2o3 Catalyst

The kinetics of the reduction of nitrogen oxide by carbon monoxide on CuO/Al2O3 catalyst (8.36 mass % CuO) were determined at temperatures between 413 and 473 K. The reaction was found to be first order in NO and zero order in CO. The observed kinetics are consistent with a rate equation derived from a mechanism proposed on the basis of IR spectroscopic measurements.

The Influence of Temperature and Concentration on Copper Deposition Kinetics in Supercritical Carbon Dioxide

2004 ◽  
Vol 812 ◽  
Author(s):  
Yinfeng Zong ◽  
James J. Watkins
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Supercritical Fluids ◽  
Zero Order ◽  
Copper Deposition ◽  
Deposition Kinetics ◽  
Zero Order Kinetics ◽  
Concentration Interval ◽  
Kinetics Of ◽  
Supercritical Carbon

AbstractThe kinetics of copper deposition by the hydrogen-assisted reduction of bis(2,2,7- trimethyloctane-3,5-dionato)copper in supercritical carbon dioxide was studied as a function of temperature and precursor concentration. The growth rate was found to be as high as 31.5 nm/min. Experiments between 220 °C and 270 °C indicated an apparent activation energy of 51.9 kJ/mol. The deposition kinetics were zero order with respect to precursor at 250 °C and 134 bar and precursor concentrations between 0.016 and 0.38 wt.% in CO2. Zero order kinetics over this large concentration interval likely contributes to the exceptional step coverage obtained from Cu depositions from supercritical fluids.

Protodemercuration of organomercuric chlorides. II. Heterocyclic mercuric chlorides

1965 ◽  
Vol 18 (10) ◽  
pp. 1513 ◽  
Author(s):  
RD Brown ◽  
AS Buchanan ◽  
AA Humffray
Keyword(s):  
Chloride Ion ◽  
Ion Pair ◽  
Zero Order ◽  
Hydrogen Ion ◽  
First Order ◽  
Entropy Effects ◽  
Kinetics Of ◽  
Complex Anions ◽  
Dominant Influence ◽  
Electron Effects

The kinetics of protodemercuration, or displacement of the HgCl group by hydrogen, have been measured for 2- and 3-furyl, 2-thienyl, and 2-selenophenylmercuric chlorides. The reactions of these compounds with aqueous alcoholic hydrochloric acid were first order in hydrogen ion, first order in RHgC1, and zero order in chloride ion, when the latter was present at concentrations less than 0.1M. At 70�, the relative rates were: 3-furyl, 1; 2-furyl, 27; 2-thienyl, 11; 2-seleno- phenyl, 25. At higher chloride concentrations, the rate increases; this is discussed in terms of formation of complex anions of the type RHgCl32- and in terms of H+Cl- ion pair attack. The dominant influence of entropy effects in the case of furan compounds emphasizes the danger of trying to account for observed relative rates in terms of π-electron effects alone.

Pseudo-Homogenous Kinetics Model for the Synthesis of Dimethyl Carbonate from Urea and Methanol with Heterogeneous Catalyst

2011 ◽  
Vol 233-235 ◽  
pp. 481-486
Author(s):  
Wen Bo Zhao ◽  
Ning Zhao ◽  
Fu Kui Xiao ◽  
Wei Wei
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Dimethyl Carbonate ◽  
Side Reaction ◽  
Order Reaction ◽  
Zero Order ◽  
Kinetics Model ◽  
First Order ◽  
Zero Order Reaction ◽  
Kinetics Of

The synthesis of dimethyl carbonate (DMC) from urea and methanol includes two main reactions: one amino of urea is substituted by methoxy to produce the intermediate methyl carbamate (MC) which further converts to DMC via reaction with methanol again. In a stainless steel autoclave, the kinetics of these reactions was separately investigated without catalyst and with Zn-containing catalyst. Without catalyst, for the first reaction, the reaction kinetics can be described as first order with respect to the concentrations of methanol and methyl carbamate (MC), respectively. For the second reaction, the results exhibit characteristics of zero-order reaction. Over Zn-containing catalyst, the first reaction is neglected in the kinetics model since its rate is much faster than second reaction. After the optimization of reaction condition, the macro-kinetic parameters of the second reaction are obtained by fitting the experimental data to a pseudo-homogenous model, in which a side reaction of DMC synthesis is incorporated since it decreases the yield of DMC drastically at high temperature. The activation energy of the reaction from MC to DMC is 104 KJ/mol while that of the side reaction of DMC is 135 KJ/mol.

Parameters Effect on Photocatalytic Reduction Kinetics of Bromate in Aqueous Dispersion of TiO2

2013 ◽  
Vol 779-780 ◽  
pp. 1658-1665
Author(s):  
Rong Shu Zhu ◽  
Fei Tian ◽  
Ling Ling Zhang ◽  
Ling Min Yu
Keyword(s):  
Aqueous Dispersion ◽  
Zero Order ◽  
Photocatalytic Reduction ◽  
Reduction Kinetics ◽  
First Order ◽  
First Order Kinetics ◽  
Zero Order Kinetics ◽  
Experimental Parameters ◽  
Pseudo First Order ◽  
Kinetics Of

This paper studied the photocatalytic reduction kinetics of bromate in aqueous dispersion of TiO2 and investigated the effects of experimental parameters, including initial concentration of BrO3-, pH, TiO2 dosage, anion and cation. The results indicate that the process of photocatalytic reduction of bromate follows a zero-order kinetics. In all the investigated experimental parameters, the initial bromate concentration, pH and anion have great effect on the photocatalytic reduction kinetics. The processes of photocatalytic reduction of bromate show the pseudo first-order kinetics at initial bromate concentration of 0.39 μmolL-1, pH=5.0, or in presence of HCO3-/CO32-, NO3-, SO42-, respectively.

Kinetics of the Heterogeneous Ozonation of Nitrated Phenols

1992 ◽  
Vol 26 (1-2) ◽  
pp. 169-180 ◽  
Author(s):  
J. P. Gould ◽  
G. V. Ulirsch
Keyword(s):  
Mass Transfer ◽  
Rate Constants ◽  
Chemical Structure ◽  
Process Analysis ◽  
Qsar Model ◽  
Zero Order ◽  
Transfer Coefficients ◽  
First Order ◽  
Kinetics Of ◽  
Phenolic Concentration

The kinetics of the heterogeneous ozonation of phenol and 27 nitrophenols representing a wide array of functional groups have been studied. In the systems examined, the process has been found to be zero order with respect to phenolic concentration which indicates mass transfer as the prime control on the process. Analysis of the first order rate constants has permitted computation of overall mass transfer coefficients for all compounds. The coefficients were sixty percent lower than the kLa values measured by others in water and showed very little variation regardless of chemical structure of the phenol. Efforts at development of a QSAR model for the kinetics were fruitless.

Mechanism of Hg(II) Oxidation of D-Galactose in Alkaline Medium

1978 ◽  
Vol 33 (6) ◽  
pp. 657-659 ◽  
Author(s):  
M. P. Singh ◽  
A. K. Singh ◽  
Mandhir Kumar
Keyword(s):  
Alkaline Medium ◽  
Reaction Rate ◽  
Reducing Sugar ◽  
Zero Order ◽  
Ion Concentration ◽  
Kinetics Of Oxidation ◽  
Ion Concentrations ◽  
First Order ◽  
Kinetics Of ◽  
Direct Proportionality

Abstract The present paper deals with the kinetics of oxidation of D-galactose by Nessler's reagent in alkaline medium. The reaction is zero order with respect to Hg(II) and first order with respect to reducing sugar. The direct proportionality of the reaction rate at low hydroxide ion concentrations shows retarding trend at higher concentrations. The reaction rate is inversely proportional to iodide ion concentration. A mechanism has been proposed taking HgI3- as the reacting species

Protodemercuration of organomercuric chlorides. I. Aromatic mercuric chlorides

1965 ◽  
Vol 18 (10) ◽  
pp. 1507 ◽  
Author(s):  
RD Brown ◽  
AS Buchanan ◽  
AA Humffray
Keyword(s):  
Hydrochloric Acid ◽  
Correlation Coefficient ◽  
Chloride Ion ◽  
Zero Order ◽  
Hydrogen Ion ◽  
First Order ◽  
Phenylmercuric Chloride ◽  
Kinetics Of

The kinetics of protodemercuration, or displacement of the HgCl group by hydrogen, have been measured for phenylmercuric chloride, and also for its meta and para methyl-, chloro-, and methoxy-substituted derivatives. The reactions of the compounds with aqueous alcoholic hydrochloric acid were first order in RHgC1, first order in hydrogen ion, and zero order in chloride ion. At 70" the relative rates, which were largely determined by entropy factors, were: phenyl, 1; p-tolyl, 7; m-tolyl, 2.4; p-chlorophenyl, 0.67; m-chlorophenyl, 0.26; p-methoxy, 150; m-methoxy, 0.71. A plot of log k against σ+ gives a ρ value of -2.44, and correlation coefficient of 0.986.

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