On the nature of the interaction of H2PdCl4 with the surface of graphite-like carbon materials Original Research Article

Adsorption of H2PdCl4 from aqueous solutions on the surface of graphite-like carbon materials proceeds through two competitive pathways: reduction, which gives rise to Pd ° particles of 6–100nm in size, and formation of π-complexes of PdCl2 with >CC< fragments of the carbon matrix: PdCl2C+2HCl←(2)H2PdCl4+C→(1)PdC+2ClC+2HCl Process (1) is localized near the exterior surface of the porous carbon particles. Process (2) takes place on the whole surface of these particles. The quantitative ratio of the adsorbed palladium species (Pd2+ and Pd °) and also the dispersion and morphology of the metallic particles depend on the mode of contact of the H2PdCl4 solution with the carbon, the composition of the gas phase, the size of the carbon particles, the chemical state of the carbon surface and the conditions of drying. The results obtained are explained in terms of the electrochemical theory of carbon reactivity.