Interaction temperature with carbonates

Gibbs potential changes, 136 Interaction temperature with carbonates, 27,35 Island-type structure, 60-81... 

It has been shown in Section III, A that a fraction of oxygen ions irreversibly adsorbed on nickel oxide at elevated temperatures (250°) reacts at room temperature with carbon monoxide to form adsorbed carbon dioxide. This interaction evidently also occurs on the surface of oxygenated or regenerated samples during the catalytic reaction (76). It has been observed, for instance, that adsorption of carbon monoxide, at room temperature, on the regenerated sample, although it decreases its electrical conductivity from 10- to IO-12 ohm- cm-, does not... 

Groszek, A.J., Avraham, I., Danon, A., and Koresh, J.E. (2002). Interaction of02, Nj and He at room temperature with carbon molecular sieves sensed by adsorption measurements. Colloid Surf. A, 208, 65-70. 

Interaction with sulfur dioxide at ambient temperature, or with carbon dioxide on warming, causes incandescence. 

Mixtures with carbon monoxide, hydrogen and methane are stable at ambient temperatures, but explode violently on sparking. Hydrogen sulfide explodes with oxygen difluoride at ambient temperature and, though interaction is smooth at... 

The temperature at which a cycloaddition reaction of a neopentylsilene takes place (detected by the elimination of LiCl) has turned out to be dependent on the reaction partners added as substrate. This implies that an interaction between the substrate and A or B or the substrate and C occurs somewhere along the reaction pathway depicted above. For the system Cl3SiCH=CH2/LiBut/R2C=NR it was observed that the imine initiates and supports the salt elimination from the species A/B. Based on the knowledge that silenes are stabilized by external donors [1] we conclude that with carbon unsaturated compounds x-donor interactions instead of cr-donor complexes may be possible as well for the lithiated species (D) as for the silene itself (E). 

Most forms of carbon interact strongly with microwaves. When irradiated at 2.45 GHz, amorphous carbon and graphite in powdered form rapidly reach ca. 1000 °C within 1 min of irradiation. An example of a solvent-free Diels-Alder reaction performed on a graphite support is shown in Scheme 4.5. Here, diethyl fuma-rate and anthracene adsorbed on graphite reacted within 1 min of microwave irradiation under open-vessel conditions to provide the corresponding cycloadduct in 92% yield [14]. The maximum temperature recorded by an IR-pyrometer was 370 °C. In other cases, it was necessary to reduce the microwave power and therefore the reaction temperature in order to avoid retro-Diels-Alder reactions [13]. 

Most forms of carbon, except diamond, which are renowned as supports for precious metal catalysts in certain applications [3], interact strongly with MW [4]. Amorphous carbon and graphite, in their powdered form, irradiated at 2.45 GHz, rapidly (within 1 min) reach very high temperatures (>1300 K). This property has been used to explain MW-assisted syntheses of inorganic solids [5], In these syntheses carbon is either a secondary susceptor which assists the initial heating but does not react with other reactants, or is one of the reactants, e. g. in the synthesis of metal carbides. MW-carbon coupling has also been widely developed ... 

For over 15 years we have conducted research utilizing metal atoms in low temperature spectroscopic and synthetic studies at Rice University.8 Our synthetic work was started in the late 1960s with the work of Krishnan, on lithium atom reactions with carbon monoxide, extended by Meier- in his studies of lithium atom reactions with water and ammonia and expanded over the next several years to include metal atom interactions with HF, H2O, H3N, H4C, and their hundreds of organic analogs—RF, R2O, ROH, R3N,. . . H3N, R4C, R3CH, etc. A most exciting aspect of... 

Figure 1 shows that decreasing temperature (250 K) results in a lower mobility of the adsorbed molecules. If the temperature is further decreased (200 K), the translational motion of the molecules is almost quenched, while the internal rotation of the methyl groups remains. Let us emphasize that in the linewidth and the relative intensity variations, there exists a greater ressem-blance between carbons 1,2 and 3, which denote a greater interaction of these carbons with the surface. 

Pyrosulphuryl Chloride, S205C12.—Rose first prepared this substance in 1838 by the interaction of sulphur trioxide and sulphur monochloride.4 It is formed by the action of many chlorides on sulphur trioxide sulphur monochloride,4 thionyl chloride,5 silicon tetrachloride,6 phosphorus pentachloride,7 phosphorus oxychloride,8 sodium chloride 9 and carbon tetrachloride 10 all yield the desired product when treated with sulphur trioxide at a suitable temperature. With sodium chloride a mixture of pyrosulphufyl chloride and sodium pyrosulphate is obtained, whilst with the exception of carbon tetrachloride and phosphorus pentachloride, which are converted into oxychlorides, all the remaining chlorides are changed into oxides ... 

The production of thiophen when acetylene interacts with sulphur vapour has already been mentioned (p. 258). That this product is not the result of a secondary reaction between acetylene and carbon disulphide follows from the fact that thiophen is only produced in quantity from these two reactants at a considerably higher temperature than that required when sulphur is used. Acetylene saturated -with carbon disulphide vapour and passed through an electrically heated tube containing broken porous pot, yields a condensate which at the optimum temperature of 700° C. contains about 10 per cent, by volume of thiophen and 10 per cent, of hydrocarbons.1... 

The selectivity of alcohol depends on the carbide preparation. A maximum in alcohol is achieved for the sample WC/Ti02 (T3) for which the preparation of the carbide combines reduction and carburization steps at moderate temperatures (respectively, 873 K and 1073 K). In this case, anionic vacancies stabilized by mixed oxides are formed, associated with carbon vacancies in mixed carbides resulting in a better interaction of carbidic and oxidic phases. On silica, ceria and zirconia, the extent of carburization is too high and the interaction of the carbide phase with the oxide support is suppressed giving larger isolated particles of tungsten carbide with low dispersion. 

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