A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Structure-Dependent Fenton Reactivity and Degradation Pathway of Methylimidazolium Ionic Liquids
https://orcid.org/0000-0002-3803-1393
Short-chain imidazolium-based ionic liquids (IBILs) substituted by methyl groups are highly water-soluble and have the potential risk of entering the water environment with wastewater. In this work, the structure-dependent Fenton reactivity and degradation pathway of methylimidazolium ionic liquids were investigated, including the influence of the proton activity and structural symmetry of IBILs. The chemical reactivity of specific sites (atoms) was quantitatively predicted by a condensed Fukui function (f A –). Aprotic IBILs ([DMIM][BF4] and [TMIM][BF4]) were more resistant to the •OH attacks than protic IBILs ([HHIM][BF4] and [HMIM][BF4]) because deprotonation reduced the f A – value of the attack sites. Structural symmetry increased the initial rate of the total organic carbon (TOC) reduction (k 0,TOC) due to the existence of symmetric Fenton reaction sites. Trimethyl-substituted [TMIM][BF4] showed the lowest TOC removal efficiency and k 0,TOC presumably because the C2-methyl substitution greatly weakened the f A – value of C2. The plausible mineralization pathways were proposed on the basis of gas chromatography coupled with mass spectrometry analyses. The more methyl substitution resulted in weaker Fenton reactivity but more oxidation pathways. For [TMIM][BF4], C2-methyl reduced the Fenton reactivity of the imidazolium skeleton but increased the oxidation opportunities of dual N-methyls.
The Fenton reactivity of methylimidazolium ionic liquids (ILs) is regulated by the proton activity and structural symmetry of ILs.
Structure-Dependent Fenton Reactivity and Degradation Pathway of Methylimidazolium Ionic Liquids
https://orcid.org/0000-0002-3803-1393
Short-chain imidazolium-based ionic liquids (IBILs) substituted by methyl groups are highly water-soluble and have the potential risk of entering the water environment with wastewater. In this work, the structure-dependent Fenton reactivity and degradation pathway of methylimidazolium ionic liquids were investigated, including the influence of the proton activity and structural symmetry of IBILs. The chemical reactivity of specific sites (atoms) was quantitatively predicted by a condensed Fukui function (f A –). Aprotic IBILs ([DMIM][BF4] and [TMIM][BF4]) were more resistant to the •OH attacks than protic IBILs ([HHIM][BF4] and [HMIM][BF4]) because deprotonation reduced the f A – value of the attack sites. Structural symmetry increased the initial rate of the total organic carbon (TOC) reduction (k 0,TOC) due to the existence of symmetric Fenton reaction sites. Trimethyl-substituted [TMIM][BF4] showed the lowest TOC removal efficiency and k 0,TOC presumably because the C2-methyl substitution greatly weakened the f A – value of C2. The plausible mineralization pathways were proposed on the basis of gas chromatography coupled with mass spectrometry analyses. The more methyl substitution resulted in weaker Fenton reactivity but more oxidation pathways. For [TMIM][BF4], C2-methyl reduced the Fenton reactivity of the imidazolium skeleton but increased the oxidation opportunities of dual N-methyls.
The Fenton reactivity of methylimidazolium ionic liquids (ILs) is regulated by the proton activity and structural symmetry of ILs.
Structure-Dependent Fenton Reactivity and Degradation Pathway of Methylimidazolium Ionic Liquids
https://orcid.org/0000-0002-3803-1393
Short-chain imidazolium-based ionic liquids (IBILs) substituted by methyl groups are highly water-soluble and have the potential risk of entering the water environment with wastewater. In this work, the structure-dependent Fenton reactivity and degradation pathway of methylimidazolium ionic liquids were investigated, including the influence of the proton activity and structural symmetry of IBILs. The chemical reactivity of specific sites (atoms) was quantitatively predicted by a condensed Fukui function (f A –). Aprotic IBILs ([DMIM][BF4] and [TMIM][BF4]) were more resistant to the •OH attacks than protic IBILs ([HHIM][BF4] and [HMIM][BF4]) because deprotonation reduced the f A – value of the attack sites. Structural symmetry increased the initial rate of the total organic carbon (TOC) reduction (k 0,TOC) due to the existence of symmetric Fenton reaction sites. Trimethyl-substituted [TMIM][BF4] showed the lowest TOC removal efficiency and k 0,TOC presumably because the C2-methyl substitution greatly weakened the f A – value of C2. The plausible mineralization pathways were proposed on the basis of gas chromatography coupled with mass spectrometry analyses. The more methyl substitution resulted in weaker Fenton reactivity but more oxidation pathways. For [TMIM][BF4], C2-methyl reduced the Fenton reactivity of the imidazolium skeleton but increased the oxidation opportunities of dual N-methyls.
The Fenton reactivity of methylimidazolium ionic liquids (ILs) is regulated by the proton activity and structural symmetry of ILs.
Structure-Dependent Fenton Reactivity and Degradation Pathway of Methylimidazolium Ionic Liquids
Zhu, Ling (author) / Cheng, Huan (author) / Han, Wenhui (author) / Liu, Mengping (author) / Qiu, Yuping (author)
ACS ES&T Water ; 1 ; 808-814
2021-04-09
Article (Journal)
Electronic Resource
English
Absorption of methylbenzene in 1-butyl-3-methylimidazolium ionic liquids
| British Library Online Contents | 2017
| British Library Online Contents | 2006
Oxidative degradation of sulfathiazole by Fenton and photo-Fenton reactions
| Online Contents | 2014
Degradation behavior of cellulose in imidazolium-based ionic liquids
| British Library Online Contents | 2012