Popis: |
A combined palladium–rhodium catalyst, generated by silica sol–gel-co-entrapment of metallic palladium and [Rh(cod) (-Cl)]2, catalyzes under ambient conditions the hydrogenation of toluene and other simple benzene derivatives. The catalyst is perfectly recyclable and promotes at 80 ◦ C and 400 psi, also the hydrogenation of polycyclic and sterically hindered arenes that are capable of penetrating the matrix pores. A synergistic effect is assumed to exist between the two metals, as either of the entrapped metallic components is a less active catalyst than the combination of both. © 2002 Elsevier Science B.V. All rights reserved. |