K. Amine et al., CATALYTIC ACTIVITY OF PLATINUM AFTER EXCHANGE WITH SURFACE-ACTIVE FUNCTIONAL-GROUPS OF CARBON-BLACKS, Journal of the Chemical Society. Faraday transactions, 91(24), 1995, pp. 4451-4458
Citations number
27
Categorie Soggetti
Chemistry Physical","Physics, Atomic, Molecular & Chemical
The deposition of platinum on various carbon blacks has been carried o
ut by forming active functional groups on the surface of the carbon su
pport, and exchanging these active groups with different platinum comp
lexes. Using H2PtCl6 solution, an aggregation rather than an exchange
takes place. In this case, the anionic platinum complexes [PtCl6](2-)
involved have a tendency to form a coagulated platinum cluster after t
he reduction process. However, using ammonium platinum chloride, an ex
change between the cationic platinum complexes and surface functional
groups takes place. The exchange process involving the divalent platin
um complex, [Pt(NH3)(4)](2+) is much faster than the one where the tet
ravalent platinum complex [Pt(NH3)(6)](4+), is involved. Transmission
electron migrograph (TEM) photographs have shown that when using Pt(NH
3)(4)Cl-2 solution for the exchange, platinum particles are extremely
small (0.75-1.7 nm) and highly dispersed on the surface of the carbon
black. A comparison of the catalytic activities of platinum supported
on various carbon blacks was also carried out. The catalytic activity
mainly depends on the particle size rather than the loading amount of
the catalyst.