Palladium sorption and reduction on sulfide mineral surfaces: An XPS and AES study

Journal Article · Mon Jan 01 04:00:00 EST 1990 · Geochimica et Cosmochimica Acta; (USA)

DOI:https://doi.org/10.1016/0016-7037(90)90200-5· OSTI ID:6692348

Hyland, M M; Bancroft, G M ^[1]

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1. Univ. of Western Ontario, London (Canada)

High resolution X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) were used to study the sorption/reduction of aqueous Na{sub 2}PdCl{sub 4} at FeS{sub 2}, PbS, and (Zn,Fe)S surfaces. Two concurrent reactions take place: the sorption of Pd(II) and the reduction of Na{sub 2}PdCl{sub 4}(aq) to Pd(0). Detailed studies on pyrite indicate the reduction is dependent on Cl{sup {minus}} and H{sup +} concentrations, which control the concentration of the electroactive species, PdCl{sub 2}(H{sub 2}O){sub 2} and/or PdCl{sub 2}(H{sub 2}O)(OH){sup {minus}}. Palladium metal deposition and crystal growth take place at high energy sites on the mineral surface. The surfaces of PbS and (Zn, Fe)S become metal-depleted, and sulfide groups are oxidized to polysulfides. Pyrite oxidation was undetected by XPS but presumably results in the formation of soluble sulfoxy species.

• OSTI ID: 6692348
• Journal Information: Geochimica et Cosmochimica Acta; (USA), Journal Name: Geochimica et Cosmochimica Acta; (USA) Vol. 54:1; ISSN GCACA; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ALKALI METAL COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
CRYSTALLIZATION
DEPOSITION
ELECTRON SPECTROSCOPY
GEOCHEMISTRY
HALIDES
HALOGEN COMPOUNDS
IRON COMPOUNDS
IRON SULFIDES
MINERALS
PALLADIUM CHLORIDES
PALLADIUM COMPOUNDS
PHASE TRANSFORMATIONS
PHOTOELECTRON SPECTROSCOPY
PLATINUM COMPOUNDS
PRECIPITATION
PYRITE
REDOX REACTIONS
REDUCTION
SEPARATION PROCESSES
SODIUM COMPOUNDS
SORPTION
SORPTIVE PROPERTIES
SPECTROSCOPY
SULFIDE MINERALS
SULFIDES
SULFUR COMPOUNDS
SURFACE PROPERTIES
TRANSITION ELEMENT COMPOUNDS
X-RAY SPECTROSCOPY