Structure of Sulfate Adsorption Complexes on Ferrihydrite

Mengqiang Zhu; Paul Northrup; Chenyang Shi; Simon J.L. Billinge; Donald L. Sparks; Glenn A. Waychunas

doi:10.1021/ez400052r

Structure of Sulfate Adsorption Complexes on Ferrihydrite

Mengqiang Zhu
, Paul Northrup
, Chenyang Shi
, Simon J.L. Billinge
, Donald L. Sparks
, Glenn A. Waychunas

Geosciences

Lawrence Berkeley National Laboratory
University of Wyoming
Columbia University
Brookhaven National Laboratory Condensed Matter Physics and Materials Science Department
University of Delaware

Research output: Contribution to journal › Article › peer-review

103 Scopus citations

Abstract

Sulfate adsorption on mineral surfaces is an important environmental chemical process. However, the structure of sulfate adsorption complexes has remained uncertain. In this study, we have determined the S-Fe distance of sulfate inner-sphere adsorption complexes on iron (Fe) oxyhydroxide (ferrihydrite) surfaces under air-dried conditions using sulfur K-edge extended X-ray absorption fine structure spectroscopy and differential X-ray pair distribution function analysis. Both approaches indicate that the S-Fe interatomic distance of the sulfate adsorption complexes is 3.22-3.25 Å, suggesting that sulfate forms bidentate-binuclear adsorption complexes on ferrihydrite surfaces. Outer-sphere complexes are also observed using infrared spectroscopic analysis. This finding clarifies the long-standing debate over the structure of sulfate adsorption complexes and has important implications for understanding the chemistry of sulfate at environmental interfaces.

Original language	English
Pages (from-to)	97-101
Number of pages	5
Journal	Environmental Science and Technology Letters
Volume	1
Issue number	1
DOIs	https://doi.org/10.1021/ez400052r
State	Published - Oct 8 2013

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title = "Structure of Sulfate Adsorption Complexes on Ferrihydrite",

abstract = "Sulfate adsorption on mineral surfaces is an important environmental chemical process. However, the structure of sulfate adsorption complexes has remained uncertain. In this study, we have determined the S-Fe distance of sulfate inner-sphere adsorption complexes on iron (Fe) oxyhydroxide (ferrihydrite) surfaces under air-dried conditions using sulfur K-edge extended X-ray absorption fine structure spectroscopy and differential X-ray pair distribution function analysis. Both approaches indicate that the S-Fe interatomic distance of the sulfate adsorption complexes is 3.22-3.25 {\AA}, suggesting that sulfate forms bidentate-binuclear adsorption complexes on ferrihydrite surfaces. Outer-sphere complexes are also observed using infrared spectroscopic analysis. This finding clarifies the long-standing debate over the structure of sulfate adsorption complexes and has important implications for understanding the chemistry of sulfate at environmental interfaces.",

author = "Mengqiang Zhu and Paul Northrup and Chenyang Shi and Billinge, \{Simon J.L.\} and Sparks, \{Donald L.\} and Waychunas, \{Glenn A.\}",

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doi = "10.1021/ez400052r",

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T1 - Structure of Sulfate Adsorption Complexes on Ferrihydrite

AU - Zhu, Mengqiang

AU - Northrup, Paul

AU - Shi, Chenyang

AU - Billinge, Simon J.L.

AU - Sparks, Donald L.

AU - Waychunas, Glenn A.

PY - 2013/10/8

Y1 - 2013/10/8

N2 - Sulfate adsorption on mineral surfaces is an important environmental chemical process. However, the structure of sulfate adsorption complexes has remained uncertain. In this study, we have determined the S-Fe distance of sulfate inner-sphere adsorption complexes on iron (Fe) oxyhydroxide (ferrihydrite) surfaces under air-dried conditions using sulfur K-edge extended X-ray absorption fine structure spectroscopy and differential X-ray pair distribution function analysis. Both approaches indicate that the S-Fe interatomic distance of the sulfate adsorption complexes is 3.22-3.25 Å, suggesting that sulfate forms bidentate-binuclear adsorption complexes on ferrihydrite surfaces. Outer-sphere complexes are also observed using infrared spectroscopic analysis. This finding clarifies the long-standing debate over the structure of sulfate adsorption complexes and has important implications for understanding the chemistry of sulfate at environmental interfaces.

AB - Sulfate adsorption on mineral surfaces is an important environmental chemical process. However, the structure of sulfate adsorption complexes has remained uncertain. In this study, we have determined the S-Fe distance of sulfate inner-sphere adsorption complexes on iron (Fe) oxyhydroxide (ferrihydrite) surfaces under air-dried conditions using sulfur K-edge extended X-ray absorption fine structure spectroscopy and differential X-ray pair distribution function analysis. Both approaches indicate that the S-Fe interatomic distance of the sulfate adsorption complexes is 3.22-3.25 Å, suggesting that sulfate forms bidentate-binuclear adsorption complexes on ferrihydrite surfaces. Outer-sphere complexes are also observed using infrared spectroscopic analysis. This finding clarifies the long-standing debate over the structure of sulfate adsorption complexes and has important implications for understanding the chemistry of sulfate at environmental interfaces.

UR - https://www.scopus.com/pages/publications/84969134752

U2 - 10.1021/ez400052r

DO - 10.1021/ez400052r

M3 - Article

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SN - 2328-8930

VL - 1

SP - 97

EP - 101

JO - Environmental Science and Technology Letters

JF - Environmental Science and Technology Letters

IS - 1

ER -

Structure of Sulfate Adsorption Complexes on Ferrihydrite

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