Molybdenum interactions

In the sulfided state the monolayer should remain intact provided molybdenum interacts with surface strongly. However, there is no data available on strength of interaction of molybdenum with sepiolite support surface. The oxygen chemisorption which is conducted on... 

Kumar, V., and Singh, M. (1980). Sulfur, phosphorus, and molybdenum interactions in relation to growth, uptake, and utilization of sulfur in soybean. Soil Sci. 129 297-304. 

The location of Q(19) corroborates the interpretation of the carbon-molybdenum interaction as double bond and justifies the use of HFIX 43forC(l). The S-values have been defined in Equations 2.3 and 2.4. 

Molybdenum is extremely resistant to attack by molten glass up to 1 000° C if sulphur is present, and up to 1 400°C in its absence. In addition, any reaction products formed by the two materials are colourless. Consequently molybdenum is used in the production of optical and soda lime glasses. Molybdenum is, however, corroded by lead glasses which lose their gloss as a result of the interaction between the two materials. ... 

MgO-supported model Mo—Pd catalysts have been prepared from the bimetallic cluster [Mo2Pd2 /z3-CO)2(/r-CO)4(PPh3)2() -C2H )2 (Fig. 70) and monometallic precursors. Each supported sample was treated in H2 at various temperatures to form metallic palladium, and characterized by chemisorption of H2, CO, and O2, transmission electron microscopy, TPD of adsorbed CO, and EXAFS. The data showed that the presence of molybdenum in the bimetallic precursor helped to maintain the palladium in a highly dispersed form. In contrast, the sample prepared from the monometallie precursors was characterized by larger palladium particles and by weaker Mo—Pd interactions. ... 

It is likely that these metals displace molybdenum from surface sites on the alumina, so that they interfere with the strong interaction of the molybdenum and aluminum which keeps the molybdenum well dispersed. 

The similarity of the results obtained for finite elusters and the infinite slab allows to eonclude in favour of the validity of the eluster model of adequate size (6 or 8 molybdenum atoms). In addition to the chemisorption of organic molecules on solid surfaces which is generally considered as a localized phenomenon, the interaction between molybdenum oxide and an adsorbate can also be represented by a loeal eomplex formed by a finite eluster and the adsorbed molecule. Indeed, the study of the evolution of the electronic properties as a funetion of the cluster size shows that, for a eluster eontaining 6 or 8 molybdenum atoms, most of the electronic properties converge towards limit values. This eonvergence is sensitive to the direction of the cluster growth. On the other hand, the electronic properties of the (001), (010) and (100) faces are not identieal, the type of surface atoms being different these results allow to predict that the characteristics of the chemisorption step will depend on the particular face on which it takes place. 

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