Acetylene, kinetics pressure

Moro-oka el al. (42,230) have reported kinetic data for the oxidation reactions of acetylene, ethylene, propene, propane, and isobutene on up to twelve different oxides and also palladium and platinum metals. Calculated parameters for the two compensation effects mentioned by these authors [i.e., those oxidation reactions of propene for which the oxygen pressure dependency exponent was <0.6 (42) and the oxidation of acetylene (230)] and for all the data given in both references are given in Table V, D, E, and F, respectively. Although similar calculations were completed for several other selected groups of related reactions, no additional significant instances of obedience of data to Eq. (2) were detected. 

A small decrease in the yield of 2-phenyl-1-vinylpyrrole (4) when RbOH and CsOH are used as the catalyst instead of KOH is a result of enhanced resinification (78ZOR1733). Large differences in the catalytic activity of alkali metal hydroxides with respect to the reaction of acetophenoneoxime with acetylene (Scheme 2) in the MOH/DMSO system at 96°C and under atmospheric pressure were confirmed in studying the kinetics of this reaction (Fig. 1). According to these data the catalytic activity increases in the following sequence [89KGS770] ... 

Figure 3 presents kinetic curves for the formation of 2-phenylpyrrole (Scheme 2) at 96°C and atmospheric C2H2 pressure in various solvents such as DMSO, HMPA, l-methyl-2-pyrrolidone, sulfolane, polyethyleneglycol (PEG) with Mm = 1000, and tetramethylurea [89KGS770]. DMSO is confirmed to possess a specific catalytic effect in this reaction, which is much superior to that of HMPA, l-methyl-2-pyrrolidone, and tetramethylurea. According to their capability to catalyze the formation of 2-phenylpyrrole from acetophenone oxime and acetylene, the solvents under consideration are arranged in the following order DMSO > HMPA l-methyl-2-pyrrolidone > sulfolane > PEG > tetra-... 

The kinetics of the reaction of cyclohexanone oxime (1) with acetylene (Equation (1)) in MOH-DMSO under atmospheric pressure was studied and quantitative data on the effect of alkaline cations on the yields of 4,5,6,7-tetrahydroindole (2) and its N-vinyl derivative 3 as well as on the reaction selectivity were obtained (08DOC(423)66). 

Acetaldehyde decomposes at a measurable rate in the temperature range 450-600 °C. At the pressures generally employed (30-300 torr), the main products are CO and CH4, which are formed in nearly equimolar amounts. Ethane, ethylene, hydrogen and propionaldehyde have also been detected. Under certain conditions small amounts of ethanol and acetylene were observed. At very low pressures the reaction products and the kinetics of the reaction seem to differ completely from normal ... 

The rate of acetylene hydrogenation on a clean Pd( 111) model catalyst has been measured using a high-pressure reactor incorporated in an ultrahigh vacuum chamber [87]. This allows the reaction to be carried out on clean, well-characterized samples. This yields a kinetic rate equation (in units of reactions/site/s) of the form ... 

The cyclotrimerization of acetylene to benzene has been studied by Rucker et al. (8J) over Pd(lll), (100), and (110) at pressure near 1 atm. The (110) surface was four-fold less active than Pd(lll) or (100), which contrasts with their relative selectivities during TDS under UHV conditions. The activity at high pressures was correlated with the fraction of the various surfaces that exposed clean Pd atoms, as probed by postreaction CO adsorption-desorption. In all cases, most of the surface was covered with a carbonaceous residue. The authors stated that the reaction rate is first-order in acetylene pressure for all three surfaces. The extensive data on the Pd(lll) surface clearly indicate first-order kinetics in that case. However, the limited data presented for Pd(110) seem (to the present author) to be better fitted by an order of —2.5, which is closer to the value of three suggested by the overall stoichiometry. 

The direct fixation of nitrogen by its reaction with CH4 in a plasma has been studied extensively At low pressure hydrogen cyanide, acetylene and hydrog i are produced A kinetic study of the reaction in the pressure range 5-30 torr... 

Plasma-Chemical Kinetics of Film Deposition in Argon-Methane and Argon-Acetylene Mixtures Under Atmospheric Pressure Conditions... 

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