Compounding with graphite

X-Ray studies confirm that platinum crystallites exist on carbon supports at least down to a metal content of about 0.03% (2). On the other hand, it has been claimed that nickel crystallites do not exist in nickel/carbon catalysts (50). This requires verification, but it does draw attention to the fact that carbon is not inert toward many metals which can form carbides or intercalation compounds with graphite. In general, it is only with the noble group VIII metals that one can feel reasonably confident that a substantial amount of the metal will be retained on the carbon surface in its elemental form. Judging from Moss s (35) electron micrographs of a reduced 5% platinum charcoal catalyst, the platinum crystallites appear to be at least as finely dispersed on charcoal as on silica or alumina, or possibly more so, but both platinum and palladium (51) supported on carbon appear to be very sensitive to sintering. 

Main uses for K alloys. Intercalation compounds with graphite are powerful solid reducing agents. See Na for Na-K alloys. 

TAA ions may make interstitial compounds with graphite [23,24] that have reducing properties similar to those of the tetraalkylammonium metals. 

The stoichiometry of the intercalation compounds with graphite depends on the occupancy of the available positions in the graphite structure by Li atoms. The fully... 

As was the case with magnesium, also highly reactive forms of zinc were made through the Rieke method and through its intercalation compounds with graphite. 

Like the alkali metals, some halogens, particularly fluorine, form intercalated compounds with graphite crystals. Reaction usually starts at 600°C. However, graphite does not react with chlorine at temperatures below that of the electric arc. 

PTFE is used in bearings due to its extremely low friction and inherent lubricity (Fig. 16.11). Compounded with graphite, bronze powder, or other fillers to reduce creep and improve wear resistance, PTFE is molded or machined into bearings for unlubricated service. 

Chlorosulfonic acid does not form intercalation compounds with graphite in the presence of an oxidant/... 

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