Oxygen pressure effects

Table II. Temperature and Oxygen Pressure Effects in Oxidation of Cyclohexanone to Adipic Acid (Reaction Conditions Cyclohexanone, 5 mL Re2(CO)10, 50 mg Solvent, 10 mL)...

Apart from drese intrinsic properties, extrinsic effects can be produced in many oxides by variation of die metal/oxygen ratio drrough control of die atmospheric oxygen potential. The p-type contribution is increased as die oxygen pressure increases, and die n-type contribution as die oxygen pressure decreases. The pressure dependence of drese contributions can usually be described by a simple power dependence dins... 

Probably the most comprehensive measurements of the effect of voids on rates are those of Cohen "" and his school. They have published data on the oxidation of pure irons for a wide temperature range and for oxygen pressures ranging from 1-3 x 10 "N/m to lOOkN/m. The interactions between void formation and oxygen uptake are complex but only at pressures below 1 3 X 10 N/m do voids have no effect. Some of their results are summarised in Fig. 1.85 over the pressure range 1-3 x 10 N/m to... 

Regions of Homogeneity of Non-stoichiometric Oxides in the Surface interaction Layers and the Effect of Oxygen Pressure on their Range of Stabiiity... 

In a broad sense similar effective double layers can be formed via gaseous adsorption or evaporation (e.g. Na evaporated on Pt electrodes deposited on fT-A Ch has been shown to behave similarly to electrochemi-cally supplied Na). In other cases, such as the effective double layer formed upon anodic polarization of Pt deposited on YSZ, the electrochemically created effective double layer appears to be unique and cannot be formed via gaseous oxygen adsorption at least under realistic (<300 bar) oxygen pressure conditions. 

Hamdi, M., Blanc, P.J., and Goma, G., A new process for red pigment production by Monascus purpureus culture on prickly pear juice and the effect of partial oxygen pressure. Bioprocess Eng., 17, 75, 1995. 

In the reaction shown above, the volume of the reaction products (2 mol CO) is seen to be much greater than that of the reactants (2 mol of solid carbon plus 1 mol of oxygen). The effect of pressure on the free energy of formation of an oxide associated with an increase in the number of gas molecules which is representative of the type of reaction in the present illustration is shown in Figure 4.2 (A). Applying the criterion of volume increase per mole accompanying reaction at standard state to the case of metal oxidation such as... 

A. Muan, The Effect of Oxygen Pressure on Phase Relations in Oxide Systems, Am. J. Sci, 256, 171-207 (1958). 

Oxygen pipelines, 47 754 Oxygen plasma etching, of lotus effect surfaces, 22 117, 119 Oxygen pressure, in oxidation reactions, 49 82... 

The effect of the partial pressure of oxygen and of CO2 is also very important for the decomposition behaviour of siderite and rhodochrosite. The formation of the iron oxides was followed by TG and by high temperature X-ray diffraction. Below 10-6 mm Hg oxygen pressure only Fe304 was formed. 

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