Palladium acetate complexes have been incorporated into polycarbonate (PC) films as a dispersion medium using tetrahydrofuran (THF). The resulting light brown-coloured homogeneous films of 10-30 wt.% Pd metal complex concentration are found to be thermally stable up to 150 degrees C, and the relatively electron rich oxygen atoms of ketone groups in polycarbonate molecules are assumed to interact with Pd complexes on the basis of their infrared spectroscopic and thermal analyses. The reaction chemistry of Pd in PC has been investigated by reacting Pd sites with small gaseous molecules such as CO, H-2, O-2, NO, and olefins in the temperature range of 25 to 150 degrees C, and various Pd-carbonyls, -hydride, -nitrosyl, and -ethylene species formed in PC are characterized. The treatment of Pd-containing PC film with H-2 gas at 120 degrees C produces small Pd metal particles of ca. 40-330 Angstrom in diameter in PC, which show various catalytic reactivities in CO oxidation, NO reduction, dimethyl carbonate formation and hydrogenation of styrene-monomer. (C) 2000 Elsevier Science B.V. All rights reserved.