On the anomalous adsorption of [Pd(edta)](2-) at the water/goethite interface: Spectroscopic evidence for two types of surface complexes
Research output: Contribution to journal › Article
The structure of palladium(II) ethylenediaminetetraacetate (edta) in aqueous solutions and its adsorption on the surface of goethite (alpha-FeOOH) were studied using extended X-ray absorption fine structure spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. The obtained results show that in aqueous solutions, Pd-edta exists as a 1:1 complex, [P(edta)](2-), with edta acting as a quadridentate ligand. On the surface of goethite, [Pd(edta)](2-) forms two different types of complexes over a pH range of 3.40-8.12. At pH < 5, [Pd(edta)](2-) adsorbs as an outer-sphere species with possible hydrogen bonding. At higher pH values, the formation of inner-sphere complexes of the cation-type sets in after a cleavage of one glycinate ring and the formation of an (edta)Pd-O-Fe linkage.
|Research areas and keywords||
Subject classification (UKÄ) – MANDATORY
|Publication status||Published - 2008|