RESONANCE RAMAN-SPECTROSCOPIC STUDY OF POLYPYRROLE IN CUZSM-5

Raman spectroscopy was employed to study the polymerization of pyrrole over a selection of copper-exchanged ZSM-5 zeolites. No polymerization occurred on catalysts of low copper content, which suggested that a critical concentration of copper(II) cations was required for reaction. On ZSM-5 materials with low Si/Al ratios, bands were detected which were characteristic of partially oxidized polypyrrole and monomeric pyrrole. The polymer was degraded in the presence of residual oxygen. It was shown that the polymer incorporated both aromatic- and quinoidal-type structures. Further, resonance Raman spectroscopy suggested that the charge carrier present in the oxidized polymer was associated with the quinoid arrangement.