Oxides thermodynamic

This calculation enables one to program easily the stoichiometric concentration, using a small calculator. If the molecule contains other atoms, silicon, tin, manganese, lead, etc, the most stable oxides thermodynamically are sought perhaps by using enthalpies of formation data listed for inorganic substances in Part Two. 

Figure 4.23 Ellingham diagram for various metal oxides. Thermodynamic data are taken from reference [21].

Most of the applications so far focus on the production of the chiral amino acid as the end product. Conversion of the chiral amino acid into the prochiral oxoacid as the end product is less common, although, for instance, Odman etal describe the use of GDH to convert L-glutamate into the higher-value 2-oxoglutarate. Similarly, Findrik et al describe in some detail the kinetics of quantitative conversion of L-methionine into 2-oxo-4-methylthiobutyric acid. In view of the relatively unfavorable equilibrium for amino acid oxidation, thermodynamic and kinetic considerations have to be carefully balanced. A high pH favors oxidative deamination, and fortunately also the PheDH has an unusually high pH optimum, above 10. However, this in itself will not secure... 

Slimane, R.B., Lau, F.S., Khinkis, M., Bingue, J.R, Saveliev, A.V., Kennedy, L.A. 2004a. Conversion of hydrogen sulfide to hydrogen by superadiabatic partial oxidation thermodynamic consideration. Int J Hydrogen Energy 29 1471-1477. 

We continue the discussion of multicomponent crystals placed in the potential chemical gradient of a component. Let us investigate what happens when a nearly stoichiometric compound crystal is brought between different potentials of its nonmetallic component (e.g., AO B203 between two different oxygen potentials). These two potentials are chosen to fall inside the stability field of the spinel phase so that the spinel will be neither reduced nor oxidized thermodynamically. We will demonstrate that the spinel can nevertheless decompose in the oxygen potential gradient. This decomposition is a purely kinetic effect and has therefore been named kinetic decomposition. 

Lu N, Yin D, Li Z, Yang J (2011) Structure of graphene oxide thermodynamics versus kinetics. J Phys ChemC 115 11991-11995... 

Petrii, O.A., Surface electrochemistry of oxides Thermodynamic and model approaches, Electrochim. Acta, 41, 2307, 1996. 

L This reaction pathway may be favored because O2, although a potent oxidant thermodynamically, is kinetically rather inert because of its electronic state. 

Further compilations or reviews on oxide thermodynamics were for example carried out by Refs. 90-93, 95, 96, by the National Bureau of Standards, U.S. [271-276], by Brewer and Rosenblatt [101,102], by Ackermann and Thom [277], as well as Brewer [103]. 

Figure 2. Comparison of NO oxidation thermodynamics limit and NO oxidation rate over...

L.B. Pankratz et ah Thermodynamic Properties of Elements and Oxides, Thermodynamic Properties of Halides, Thermodynamic Data for Mineral Technology, US Bur. of Mines, Buii. 672 (Elements and Oxides), 1982, Bull. 674 (Halides), 1984, Bull. 677 (Data for Mineral Tfechnology), 1984, Supt. of Docs. US. Government of Printing Office, Washington, D.C., USA, 1982-1984. 

Point-defect ordering (e.g., vacancy-dopant pairs) leads to interesting complications. Preparation conditions themselves (e.g., oxygen partial pressure and temperature in oxides) thermodynamically define and control this defect content and structure. It is important to realize that point defects are thermodynamically allowed and defined they are not anomalous in the least. Therefore, undoped, high-purity compounds may exhibit sizable nonstoichiometry due to intrinsic point defects. Doping (intentional addition of an impurity) allows one to precisely control the point-defect content and nonstoichiometry and, thereby, the properties. Transport properties are influenced by the point defects. Electrical conduction (hole or electron transport) and solid state diffusion of atoms generally vary with the quantity and type of point defects. 

Coke formation is most critical with respect to partial oxidation. Thermodynamic calculations of Seo et al. [66] performed for the partial oxidation of methane showed that a suprastoichiometric 0/C ratio of 1.2 (equivalent to an air ratio X of 0.3) is required to prevent carbon formation (see Figure 4.17). This means that a certain degree of total oxidation is required to prevent carbon formation. However, coke... 

F. Yang, and V. Hlavacek, Carbochlorination of tantalum and niobium oxides, Thermodynamic simulation and kinetic modeling, AIChE J, 45(1999), 581-589. 

The stability of acetic acid in basin brines at temperatures above which bacteria are active depends on the rates of the various reactions in which the acid participates. Under geologically relevant hydrothermal conditions, carboxylic acids are likely to undergo either decarboxylation or oxidation. Thermodynamic calculations of the decarboxylation reaction in Eq. (4) at 100°C (Shock 1988, 1989) indicate that, given methane and carbon dioxide fugacities achievable in natural waters, virtually no acetic acid/acetate should persist at equilibrium. It will be shown here that the persistence of acetic acid in basin brines for geologically meaningful time periods is in keeping with experimentally observed rates for the decarboxylation process. 

The sulfides of the base steel (FeCrMnLNi) were almost pure MnS. Those of the 304 type grade were (Mn,Cr)S with about 5% Cr substituted to Mn in the sulfide. FeCrMnLNi + Ce steel shows only Ce sulfides and FeCrMnLNi + Ca steel shows Ca sulfides (in shell around the oxides). Thermodynamics predicts that Sulfide solubility ranges as ... 

Whitten, K.W. Gailey, K.D. Oxidation-reduction reactions, and electrochemistry. General Chemistry with Qualitative Analysis 2nd Ed. CBS College Publishing Philadelphia, 1984 617-658. Weast, R.C. Astle, M.J. Heat of formation of inorganic oxides, thermodynamic properties of the elements, thermodynamic properties of the oxides, and selected values of chemical thermodynamic... 

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