甲醇催化分解动力学之研究

甲醇的裂解产物为H_2与CO,故甲醇被视为一种方便、安全的贮氢材料,可作为汽油的代用燃料;其裂解气作为保护气氛可广泛应用于热处理工业。甲醇裂解有两种方法,高温热裂解(约930℃)与低温催化裂解(约300℃)由于低温催化裂解有诸多优点,在工业上的应用正在发展。     

NOx在固体电解质电解池上的电化学消除

 综述了近年来利用固体电解质电解池消除NO的研究进展．重点总结了电化学消除NO研究体系、电化学消除NO分解机制、O2－在固体电解质电解池中传导的控速步骤、电极种类和形态对NO分解性能的影响以及直流与交流电作用的差异等几个方面的研究结果．在RuO2—Ag—YSZ—Pd电解池上实现的NO选择性分解是迄今为止的最佳结果，500℃下NO的转化率为31．8％，NO的分解活性是O2的分解活性的13倍．该领域今后研究的主要方向是，进一步提高NO分解相对于共存O2离子化的选择性、降低O2－在阴极界面处的传导阻力和探寻可在更低温度传导O2－的新的固体电解质     

General application of jäntti's method for the fast calculation of sorption equilibrium

On the basis of a molecular model for adsorption kinetics Jäntti introduced a method to calculate equilibriums shortly after a change of the pressure of the sorptive gas. In the present paper we show that this method is useful in many more situations than those intended originally.     

Kinetics of thermoset cure and polymerization in the glass transition region

A theoretical approach to thermoset cure kinetics based on Arrhenius kinetics and mobility was developed by considering the activation of the reacting group and chain mobility as elementary steps for reaction. This extended kinetic equation was successfully applied to the curing of an epoxy by an amine, the trimerization of a cyanate, and to the polymerization of methyl methacrylate. Full agreement between theory and experimental data was obtained in all cases. The activation energies for chain mobility were exceptionally low (0.3–1 kJ/mol for bisphenol-A-based epoxy and cyanate) which indicates that the structural units must undergo only small-angle rotational oscillations to allow a reaction. A theoretical time–temperature–transformation (TTT) diagram is also presented. © 1993 John Wiley & Sons, Inc.     

Modeling Studies of the Formation and Destruction of NO in Pulsed Barrier Discharges in Nitrogen and Air

This paper presents the results of modeling studies on the formation and destruction of NO in pulsed barrier discharges in nitrogen and air. The goals of this work are to identify the major processes involved in the formation and destruction of NO in air discharges, to distinguish between oxidative and reductive paths for NO destruction, to explore the potential importance of excited state reactions, to evaluate the role of water in such systems, and to identify the final products in the absence of heterogeneous processes. In all cases, the systems were modeled with 100×10^–4% (100 ppm) of added NO, with and without 3% added water. The focus in all of this work is chemistry in the post-pulse regime.     

Obtaining Kinetic Parameters by Modulated Thermogravimetry

A new technique, called modulated thermogravimetry, is introduced as a tool for obtaining continuous kinetic information for decomposition and volatilization reactions. The approach makes use of an oscillatory temperature program to obtain kinetic parameters during a mass loss. MTGA™ may be used under quasi-isothermal conditions to observe a single mass loss or may be combined with linear heating rate or Hi-Res™ controlled rate thermogravimetry to scan from one mass loss region to another. Results obtained are in agreement with those obtained by other kinetic methods. This revised version was published online in July 2006 with corrections to the Cover Date.     

Polychronous kinetics with nonstationary rate constants. Effect of a medium

Characteristic features of the kinetics of solid-state cage reactions with distributed parameters of the relaxing matrix were considered. Depending on the ratio of the constants of the reaction rate and relaxation of environment, the kinetics of chemical conversions can be either exponential or nonexponential. Plausible reasons for the unsteady-state character of the kinetics of the processes of two types,viz., the reactions of alkyl radicals in amorphous alcohol matrices and conversions in biological systems, were discussed. The main reason for the unsteady-state character of the reactions of the first type is a dispersion of the equilibrium distances between the reagents. Kinetics of the reactions of the second type, such as rebinding of the ligands in the heme-containing proteins (e.g., in myoglobin), is determined by the distances in the pairs of reagents and the relaxation transitions. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 469–476, March, 1997.