Mechanism of Increased Retention of Atomic Hydrogen on Moderately Sulfidated Zero-Valent Iron Surfaces

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15640%2F25%3A73632073" target="_blank" >RIV/61989592:15640/25:73632073 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/acs.langmuir.5c04136" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.langmuir.5c04136</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.langmuir.5c04136" target="_blank" >10.1021/acs.langmuir.5c04136</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mechanism of Increased Retention of Atomic Hydrogen on Moderately Sulfidated Zero-Valent Iron Surfaces

Popis výsledku v původním jazyce

Sulfidation represents a promising approach to increase the reactivity, selectivity, and longevity of zero-valent iron (ZVI) in groundwater remediation applications. Recent studies suggest that reductive reactions mediated via adsorbed H* may dominate the degradation of prominent contaminants, such as chlorinated ethenes, on sulfidated ZVI (S-ZVI) surfaces with moderate S coverage, challenging the initially proposed major role of direct electron transfer. This study employs density functional theory to investigate how S coverage and surface corrosion influence H* formation, stability, mobility, and recombination at S-ZVI surfaces at atomic resolution. Our calculations reveal that sulfidation suppresses water adsorption and H* formation via water dissociation, while also weakening H* adsorption affinity on ZVI. However, as surface oxidation also hinders H* adsorption and promotes H* recombination, S-ZVI with moderate (similar to 1 4 monolayer) S coverage retains more reduced Fe sites, which are favorable for H* adsorption, compared to the corroded ZVI surface. Adsorbed H* at the reduced Fe sites exhibits restricted mobility near S atoms, limiting H* recombination and increasing its availability for contaminant degradation. These findings provide a fundamental mechanistic understanding of increased H* retention at S-ZVI surfaces with moderate S coverage, with implications for the role of H*-mediated reactions in these systems.

Název v anglickém jazyce

Mechanism of Increased Retention of Atomic Hydrogen on Moderately Sulfidated Zero-Valent Iron Surfaces

Popis výsledku anglicky

Sulfidation represents a promising approach to increase the reactivity, selectivity, and longevity of zero-valent iron (ZVI) in groundwater remediation applications. Recent studies suggest that reductive reactions mediated via adsorbed H* may dominate the degradation of prominent contaminants, such as chlorinated ethenes, on sulfidated ZVI (S-ZVI) surfaces with moderate S coverage, challenging the initially proposed major role of direct electron transfer. This study employs density functional theory to investigate how S coverage and surface corrosion influence H* formation, stability, mobility, and recombination at S-ZVI surfaces at atomic resolution. Our calculations reveal that sulfidation suppresses water adsorption and H* formation via water dissociation, while also weakening H* adsorption affinity on ZVI. However, as surface oxidation also hinders H* adsorption and promotes H* recombination, S-ZVI with moderate (similar to 1 4 monolayer) S coverage retains more reduced Fe sites, which are favorable for H* adsorption, compared to the corroded ZVI surface. Adsorbed H* at the reduced Fe sites exhibits restricted mobility near S atoms, limiting H* recombination and increasing its availability for contaminant degradation. These findings provide a fundamental mechanistic understanding of increased H* retention at S-ZVI surfaces with moderate S coverage, with implications for the role of H*-mediated reactions in these systems.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/EH22_008%2F0004587" target="_blank" >EH22_008/0004587: Technologie za hranicí nanosvěta</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

LANGMUIR

ISSN

0743-7463

e-ISSN

1520-5827

Svazek periodika

41

Číslo periodika v rámci svazku

41

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

14

Strana od-do

"28193–28206"

Kód UT WoS článku

001590476300001

EID výsledku v databázi Scopus

2-s2.0-105019079354