Efficient electrocatalytic valorization of chlorinated organic water pollutant to ethylene

Chungseok Choi; Xiaoxiong Wang; Soonho Kwon; James L Hart; Conor L Rooney; Nia J Harmon; Quynh P Sam; Judy J Cha; William A Goddard 3rd; Menachem Elimelech; Hailiang Wang

doi:10.1038/s41565-022-01277-z

Efficient electrocatalytic valorization of chlorinated organic water pollutant to ethylene

Nat Nanotechnol. 2023 Feb;18(2):160-167. doi: 10.1038/s41565-022-01277-z. Epub 2022 Dec 19.

Authors

Chungseok Choi^#^{1

2}, Xiaoxiong Wang^#³, Soonho Kwon^#⁴, James L Hart⁵, Conor L Rooney^{1

2}, Nia J Harmon^{1

2}, Quynh P Sam⁵, Judy J Cha^{2

5

6}, William A Goddard 3rd⁷, Menachem Elimelech⁸, Hailiang Wang^{9

10}

Affiliations

¹ Department of Chemistry, Yale University, New Haven, CT, USA.
² Energy Sciences Institute, Yale University, West Haven, CT, USA.
³ Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA.
⁴ Materials and Process Simulation Center (MSC), California Institute of Technology, Pasadena, CA, USA.
⁵ Department of Materials Science and Engineering, Cornell University, Ithaca, NY, USA.
⁶ Department of Mechanical Engineering and Materials Science, Yale University, West Haven, CT, USA.
⁷ Materials and Process Simulation Center (MSC), California Institute of Technology, Pasadena, CA, USA. wag@caltech.edu.
⁸ Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, USA. menachem.elimelech@yale.edu.
⁹ Department of Chemistry, Yale University, New Haven, CT, USA. hailiang.wang@yale.edu.
¹⁰ Energy Sciences Institute, Yale University, West Haven, CT, USA. hailiang.wang@yale.edu.

^# Contributed equally.

PMID: 36536043
DOI: 10.1038/s41565-022-01277-z

Abstract

Electrochemistry can provide an efficient and sustainable way to treat environmental waters polluted by chlorinated organic compounds. However, the electrochemical valorization of 1,2-dichloroethane (DCA) is currently challenged by the lack of a catalyst that can selectively convert DCA in aqueous solutions into ethylene. Here we report a catalyst comprising cobalt phthalocyanine molecules assembled on multiwalled carbon nanotubes that can electrochemically decompose aqueous DCA with high current and energy efficiencies. Ethylene is produced at high rates with unprecedented ~100% Faradaic efficiency across wide electrode potential and reactant concentration ranges. Kinetic studies and density functional theory calculations reveal that the rate-determining step is the first C-Cl bond breaking, which does not involve protons-a key mechanistic feature that enables cobalt phthalocyanine/carbon nanotube to efficiently catalyse DCA dechlorination and suppress the hydrogen evolution reaction. The nanotubular structure of the catalyst enables us to shape it into a flow-through electrified membrane, which we have used to demonstrate >95% DCA removal from simulated water samples with environmentally relevant DCA and electrolyte concentrations.

Abstract

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