Redox Transformation of Platinum Mediated by Natural Organic Matter Revealed by X-ray Absorption Spectroscopy
Abstract
Platinum (Pt) is an emerging environmental contaminant due to its increasing anthropogenic use, yet the processes controlling its speciation remain poorly understood. Here, we investigate Pt redox transformations in the presence of natural organic matter (NOM) using X-ray absorption spectroscopy (XAS). Under anoxic conditions, NOM promotes the progressive reduction of Pt(IV) to Pt(II), with Pt(II) detectable within 24 h and only ~10% of Pt(IV) remaining after two months. In contrast, no reduction occurs under oxic conditions. The resulting Pt(II) is predominantly associated with reduced sulfur functional groups, highlighting the role of thiols in controlling Pt speciation. These results reveal a previously overlooked pathway for Pt transformation mediated by NOM. Such redox processes are likely to control Pt speciation in reducing environments including stratified freshwater water columns, hyporheic sediments, wetlands and saturated soils. The formation of reduced Pt species may enhance Pt mobility, bioavailability, and potential toxicity, with important consequences for its environmental fate.
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BibTeX
@article{doare2026redox,
title = {{Redox Transformation of Platinum Mediated by Natural Organic Matter Revealed by X-ray Absorption Spectroscopy}},
author = {Justine Le Doaré and Marc Benedetti and Valentine Vergote-Coudournac and Alexandre Gelabert and Rémi Marsac and Gautier Landrot and Charlotte Catrouillet},
journal = {Environmental Science and Technology},
year = {2026},
month = sep,
doi = {10.1021/acs.est.6c12783},
url = {https://u-paris.hal.science/hal-05767221v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Redox Transformation of Platinum Mediated by Natural Organic Matter Revealed by X-ray Absorption Spectroscopy
AU - Justine Le Doaré
AU - Marc Benedetti
AU - Valentine Vergote-Coudournac
AU - Alexandre Gelabert
AU - Rémi Marsac
AU - Gautier Landrot
AU - Charlotte Catrouillet
PY - 2026
DA - 2026/09/25
JO - Environmental Science and Technology
DO - 10.1021/acs.est.6c12783
UR - https://u-paris.hal.science/hal-05767221v1
AB - Platinum (Pt) is an emerging environmental contaminant due to its increasing anthropogenic use, yet the processes controlling its speciation remain poorly understood. Here, we investigate Pt redox transformations in the presence of natural organic matter (NOM) using X-ray absorption spectroscopy (XAS). Under anoxic conditions, NOM promotes the progressive reduction of Pt(IV) to Pt(II), with Pt(II) detectable within 24 h and only ~10% of Pt(IV) remaining after two months. In contrast, no reduction occurs under oxic conditions. The resulting Pt(II) is predominantly associated with reduced sulfur functional groups, highlighting the role of thiols in controlling Pt speciation. These results reveal a previously overlooked pathway for Pt transformation mediated by NOM. Such redox processes are likely to control Pt speciation in reducing environments including stratified freshwater water columns, hyporheic sediments, wetlands and saturated soils. The formation of reduced Pt species may enhance Pt mobility, bioavailability, and potential toxicity, with important consequences for its environmental fate.
SN - 0013-936X
SN - 1520-5851
ER -