Generation of atomic hydrogen by Ni-Fe hydroxides: Mechanism and activity for hydrodechlorination of trichloroethylene

Jia Deng; Enlai Gao; Feng Wu; Zhixiong You; Xiaozhong Li; Shuxian Gao; Li-Zhi Huang

doi:10.1016/j.watres.2021.117802

Generation of atomic hydrogen by Ni-Fe hydroxides: Mechanism and activity for hydrodechlorination of trichloroethylene

Water Res. 2021 Dec 1:207:117802. doi: 10.1016/j.watres.2021.117802. Epub 2021 Oct 26.

Authors

Jia Deng¹, Enlai Gao², Feng Wu³, Zhixiong You³, Xiaozhong Li³, Shuxian Gao⁴, Li-Zhi Huang⁵

Affiliations

¹ School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, China.
² School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, PR China.
³ School of Resources and Environmental Science, Wuhan University, Wuhan, PR China.
⁴ CAS Key Laboratory of Urban Pollutant Conversion, Department of Applied Chemistry, University of Science and Technology of China, Hefei, 230026, China.
⁵ School of Civil Engineering, Wuhan University, No. 8, East Lake South Road, Wuhan, PR China; State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, 430072, China. Electronic address: lizhihuang@whu.edu.cn.

PMID: 34731670
DOI: 10.1016/j.watres.2021.117802

Abstract

Atomic hydrogen (H•) is highly reactive for the hydrodechlorination of trichloroethylene (TCE). In this work, we found that the coprecipitation of Ni²⁺ and Fe²⁺ at neutral pH led to an unprecedented catalytic generation of H•. The generated H• effectively dechlorinate TCE to nontoxic ethylene and ethane, and Fe²⁺ is the only electron donor. The abundant adsorbed H• produced with a Ni/Fe ratio of 0.4 enhances hydrogen evolution reaction causing a low efficiency for hydrodechlorination. In contrast, the active absorbed H• is generated in the crystal lattice of Ni-Fe hydroxides with a Ni/Fe ratio of 3.0 causing highly efficient hydrodechlorination of TCE. This work not only reveals the mechanism of catalytic hydrodechlorination by Ni-Fe hydroxides at neutral pH, but also provides a novel approach to detoxify TCE in contaminated water using facile precipitated Ni-Fe hydroxides.

Keywords: Active hydrogen species; Electron transfer; Hydrodechlorination; Ni-Fe hydroxides.

MeSH terms

Catalysis
Hydrogen
Hydroxides
Trichloroethylene*
Water Pollutants, Chemical*

Substances

Hydroxides
Water Pollutants, Chemical
Trichloroethylene
Hydrogen