High-temperature studies reduction

This Study has shown that reasonably uniform platinum crystallites can be made on y-alumlna, and that platinum and palladium can be segregated and maintained In that form for the most part even after exposure to high temperature oxidation-reduction conditions. Highly dispersed clusters of palladium, nickel, cobalt, and Iron can be observed. Cluster size determination could not be accurately made because of the lack of contrast between the cluster and the support. The marginal detectability by EDS for these clusters enabled elemental Identification to be made, however, mass uniformity determinations could not be made. 

Creep Resistsince. Studies on creep resistance of particulate reinforced composites seem to indicate that such composites are less creep resistant than are monolithic matrices. Silicon nitride reinforced with 40 vol % TiN has been found to have a higher creep rate and a reduced creep strength compared to that of unreinforced silicon nitride. Further reduction in properties have been observed with an increase in the volume fraction of particles and a decrease in the particle size (20). Similar results have been found for SiC particulate reinforced silicon nitride (64). Poor creep behavior has been attributed to the presence of glassy phases in the composite, and removal of these from the microstmcture may improve the high temperature mechanical properties (64). 

A greater hindrance for paleoclimate studies, however, is that the traditional method required reduction in an all metal vacuum line at high temperature (in externally-heated nickel reaction vessels) with bromine pentafluoride (BrFs), a highly reactive gas (Clayton and Mayeda 1963). Handling this material in anything other than a dedicated geochemistry laboratory has proven extremely difficult and dangerous (Chivas 1984). 

They have been prepared with several anions,332-335 the tetrafluoroborate salt exhibits SA and Sc phases332,333 but the triflate shows a nematic phase 334 One of the problems in studying these complexes was the very high temperatures at which the phases existed and the fact that decomposition was often observed in the upper reaches of the SA phases. Reduction of these temperatures was achieved by changing the small anions for dodecyl sulfate that also make that more materials exhibit nematic SA and Sc phases, and another more viscous phase appeared, named cubic phase So- With the anion octyl sulfate336 the crystal structure of one of the complex with 4-metoxystilbazole could be achieved (20), with this anion the cubic phase was not present. 

In this study butyl acetate (AcOBu) was hydrogenolysed to butanol over alumina supported Pt, Re, RePt and Re modified SnPt naphtha reforming catalysts both in a conventional autoclave and a high throughput (HT) slurry phase reactor system (AMTEC SPR 16). The oxide precursors of catalysts were characterized by Temperature-Programmed Reduction (TPR). The aim of this work was to study the role and efficiency of Sn and Re in the activation of the carbonyl group of esters. 

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