Kinetics of the Attack of Molybdenum by Dissociated Chlorine<sup>1</sup>

Rosner, Daniel E.; Allendorf, H. D.

doi:10.1021/j100782a036

Cited by 20 publications

(11 citation statements)

References 2 publications

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“…In the case of adsorption of chlorine on the metal surface of niobium, tantalum, molybdenum, and tungsten, the adsorption has been described to follow a mechanism, which involves an activated step, while for nickel this whole reaction was shown to be very fast and leads to fully dissociated and chemically adsorbed chlorine atoms as discussed, e.g., by Rosner and Allendorf or McKinley and Shuler . Therefore, the activation energy for the dissociative adsorption on refractory metals is much higher than on nickel .…”

Section: Mathematical Approachmentioning

confidence: 99%

Kinetics of volatilization of high temperature corrosion products and its application to chlorine corrosion

Rammer

Galetz

2016

Materials & Corrosion

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Operating atmospheres of many industrial high temperature processes contain a certain amount of halogens, in most cases chlorine. Halogens have the tendency of forming volatile metal chlorides of the general formula MxCly, which are well known to play a critical role in high temperature corrosion processes, when present at a significant amount. Thermodynamic calculations give a valuable hint, whether a reaction product can occur and how volatile such products can potentially be, when the partial pressures are calculated. However, such calculations reflect thermodynamically stable conditions, while in open systems the local kinetics control the process of surface reactions. For each specific condition, the reaction rates and thus the corrosion rates have to be determined. In previous work, we have shown that corrosion kinetics which lead to the formation of volatile products follows different steps. In this work, a mathematical model is developed in which the different steps, which are required for the formation of metal chlorides and their removal from the surface are described. It is assumed that the slowest of such formation or transport steps determines the kinetics of high temperature corrosion. The application of this model on the literature data shows that by this model it becomes possible to identify the slowest and therefore rate determining step.

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Section: Mathematical Approachmentioning

confidence: 99%

Kinetics of volatilization of high temperature corrosion products and its application to chlorine corrosion

Rammer

Galetz

2016

Materials & Corrosion

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“…They can be described by the mechanisms of heterogeneous catalysis . According to these theories, the chlorination of the refractory metals tungsten, molybdenum, niobium, and tantalum follows most probably a Rideal‐type of mechanism where the surface is first covered with dissociated chlorine atoms and the chlorine layer is subsequently attacked by further chlorine from the surrounding gas phase .…”

Section: Reaction Mechanisms Of the High Temperature Chlorination Of mentioning

confidence: 99%

“…This leads to much lower adsorption of chlorine on the surface. Rosner et al describe this phenomenon by the so‐called “sticking probability”

\in

\in = \frac{a d s o r b e d C l}{i m p a c t i n g C l_{2}}

…”

Section: Reaction Mechanisms Of the High Temperature Chlorination Of mentioning

confidence: 99%

Refractory metals and nickel in high temperature chlorine‐containing environments ‐ thermodynamic prediction of volatile corrosion products and surface reaction mechanisms: a review

Galetz

Rammer

Schütze

2015

Materials & Corrosion

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Thermodynamic calculations are an important tool for prediction of chemical reactions. In many cases the results help to understand and describe the experimental observations. In others, especially if reaction kinetics play a major role, their predictive value can be rather limited and the projected results have to be treated with care. One such case are high temperature chlorine corrosion conditions. For example, thermodynamically a similar corrosion behavior of nickel and molybdenum is predicted in chlorine‐containing atmospheres at low oxygen partial pressures. In contrast to their calculated similarity, experimental results showed much higher resistance of molybdenum against the chlorinating attack. Above 800 °C nickel is rapidly consumed, whereas molybdenum remains almost inert. This paper reviews the literature on the corrosion mechanisms and kinetics of nickel and molybdenum in chlorine‐containing environments as well as in mixed oxygen‐chlorine‐containing atmospheres. Based on the literature review, differences in their reaction kinetics are discussed, taking into account the deviation from an ideal thermodynamic correlation between the partial pressure and the reaction kinetics via the often used Hertz‐Langmuir equation. Finally it is shown that the findings concerning the special characteristics of molybdenum and nickel and the conclusions drawn from experimental observations on high temperature chlorine corrosion can also be transferred to other metals.

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“…[27]. There are also classical models illustrating the physics [28]. The hamiltonian (4) has many different parametrizations.…”

Section: A General Basicsmentioning

confidence: 99%

Testing CPT symmetry with correlated neutral mesons

Roberts

2017

Phys. Rev. D

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This work gives a general overview of phenomenology developed for neutral-meson searches for CPT violation in the framework of the Standard-Model Extension with focus on meson factories. It gives a comparison of notations and fundamental approach in the formalism used by the different experiments. Asymmetries and possible experimental investigations are presented for tests of the momentum-dependent phenomenological parameter of CPT violation in correlated neutral-meson oscillations. The general results apply to any mesons produced as correlated meson pairs and address the issue of decoherence as a consequence of direction dependence. An analysis is given considering kinematics and orientation of the improved Belle II experiment.

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Kinetics of the Attack of Molybdenum by Dissociated Chlorine¹

Cited by 20 publications

References 2 publications

Kinetics of volatilization of high temperature corrosion products and its application to chlorine corrosion

Kinetics of volatilization of high temperature corrosion products and its application to chlorine corrosion

Refractory metals and nickel in high temperature chlorine‐containing environments ‐ thermodynamic prediction of volatile corrosion products and surface reaction mechanisms: a review

Testing CPT symmetry with correlated neutral mesons

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Kinetics of the Attack of Molybdenum by Dissociated Chlorine1

Cited by 20 publications

References 2 publications

Kinetics of volatilization of high temperature corrosion products and its application to chlorine corrosion

Kinetics of volatilization of high temperature corrosion products and its application to chlorine corrosion

Refractory metals and nickel in high temperature chlorine‐containing environments ‐ thermodynamic prediction of volatile corrosion products and surface reaction mechanisms: a review

Testing CPT symmetry with correlated neutral mesons

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Product

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Kinetics of the Attack of Molybdenum by Dissociated Chlorine¹