title: Local structure and speciation of platinum in fresh and road-aged North American sourced vehicle emissions catalysts: an X-ray absorption spectroscopic study.
abstract: Given emerging concerns about the bioavailability and toxicity of anthropogenic platinum compounds emitted into the environment from sources including vehicle emission catalysts (VEC), the platinum species present in selected North American sourced fresh and road-aged VEC were determined by Pt and Cl X-ray absorption spectroscopy. Detailed analysis of the Extended X-ray Absorption Fine Structure at the Pt L3 and L2 edges of the solid phase catalysts revealed mainly oxidic species in the fresh catalysts and metallic components dominant in the road-aged catalysts. In addition, some bimetallic components (Pt-Ni, Pt-Pd, Pt-Rh) were observed in the road-aged catalysts from supporting Ni-, Pd-, and Rh-K edge XAS studies. These detailed analyses allow for the significant conclusion that this study did not find any evidence for the presence of chloroplatinate species in the investigated solid phase of a Three Way Catalyst or Diesel Oxidation Catalysts.
authors.affiliation: Johnson Matthey Technology Centre , Blount's Court, Sonning Common, Reading RG4 9NH, United Kingdom.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Ash
authors.forename: David A
authors.initials: DA
authors.lastname: Boyd
authors.forename: Timothy I
authors.initials: TI
authors.lastname: Hyde
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Keating
authors.forename: Gabriele
authors.initials: G
authors.lastname: Randlshofer
authors.forename: Klaus
authors.initials: K
authors.lastname: Rothenbacher
authors.forename: Gopinathan
authors.initials: G
authors.lastname: Sankar
authors.forename: James J
authors.initials: JJ
authors.lastname: Schauer
authors.forename: Martin M
authors.initials: MM
authors.lastname: Shafer
authors.forename: Brandy M
authors.initials: BM
authors.lastname: Toner
mesh_terms: D002384:Catalysis; D005742:Gasoline / Q000032:analysis; D006801:Humans; D018986:Motor Vehicles; D009656:North America; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry*; D012015:Reference Standards; D013052:Spectrometry, X-Ray Emission; D013997:Time Factors; D001335:Vehicle Emissions / Q000032:analysis*; D056928:X-Ray Absorption Spectroscopy
chemical_list: D005742:Gasoline; D001335:Vehicle Emissions; D010984:Platinum