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 journalArticle

Abstract

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.

Details

Authors
External organisations
  • External Organization - Unknown
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Earth and Related Environmental Sciences
Original languageEnglish
Pages (from-to)483-489
JournalLangmuir
Volume24
Publication statusPublished - 2008
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes

Bibliographic note

2