Supported bimetallic polymers of porphyrins as new heterogeneous catalyst

New heterogeneous catalytic systems of mono and bimetallic polymeric porphyrinic structures confined to An surface are described. The solid materials were characterized by AFM, SEM and EDS/EDX techniques. The polymeric films have been deposited by consecutive voltammetric cycles. The appearance of a peak at 380 mV (vs. Ag/AgCl), is only observed in the first cathodic scan of the bimetallic structures and was attributed to Cu(III)/Cu(II) reduction in polyFeCuPP. In all the cases studied, the bimetallic structures were up to 3.5 times more efficient catalyst than the corresponding monometallic. PolyCoCuPP is intrinsically weaker than polyFeCuPP. Nevertheless, the mass deposited is significantly higher (80%). For this reason, polyCoCuPP is considered the best catalyst under practical considerations. The use of a solid catalyst with a small amount of H2O2, in aqueous solution, makes this oxidation an environmentally benign chemical process. (C) 2007 Elsevier B.V. All rights reserved.