SYNTHESIS, CHARACTERIZATION AND CATALYTIC PROPERTIES OF PALLADIUM-CONTAINING ELECTROACTIVE POLYMERS

The chemical deposition of palladium into the matrix of the electroact ive polymers, polyaniline and polypyrrole, was investigated. The proce ss involved the treatment of the electroactive polymers with acid solu tions containing Pd(II) ions. It was found that the rate of palladium uptake was significantly higher when the polymers were reduced to thei r lowest oxidation state, and the rate of the reaction and the state o f the palladium incorporated into the polymer matrix were dependent on the nature of the anions in solution. The Pd-containing electroactive polymers were characterized by X-ray photoelectron spectroscopy (XPS) , thermogravimetric analysis, inductively coupled plasma emission spec troscopy, and surface area and particle size measurements. The catalyt ic properties have been studied in the hydrogenation of nitrobenzene a nd compared to those of palladium supported on aluminum oxide and PdCl 2. The XPS analysis of the Pd-containing polymer catalysts showed only slight changes in the state of the palladium and the polymer support after hydrogenation reaction. (C) 1998 Elsevier Science S.A. All right s reserved.