Electrochemical Reduction and Oxidation of Chlorinated Aromatic Compounds Enhanced by the Fe-ZSM-5 Catalyst: Kinetics and Mechanisms

Yuexuan Li; Yun Liu; Xuan Zhang; Kun Tian; Ding Tan; Xiaosan Song; Ping Wang; Qian Jiang; Junhe Lu

doi:10.1021/acsomega.2c04458

Electrochemical Reduction and Oxidation of Chlorinated Aromatic Compounds Enhanced by the Fe-ZSM-5 Catalyst: Kinetics and Mechanisms

ACS Omega. 2022 Sep 10;7(37):33500-33510. doi: 10.1021/acsomega.2c04458. eCollection 2022 Sep 20.

Authors

Yuexuan Li^{1

2}, Yun Liu^{1

3}, Xuan Zhang², Kun Tian^{1

3}, Ding Tan^{1

3}, Xiaosan Song², Ping Wang², Qian Jiang¹, Junhe Lu⁴

Affiliations

¹ Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China.
² Lanzhou Jiaotong University, Lanzhou 730070, China.
³ University of Chinese Academy of Sciences, Beijing 100000, China.
⁴ College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China.

Abstract

Devising cost-effective electrochemical catalyst system for the efficient degradation of chlorinated aromatic compounds is urgently needed for environmental pollution control. Herein, a Fe-ZSM-5 zeolite was used as a suspended catalyst to facilitate the degradation of lindane as a model chlorinated pesticide in an electrochemical system consisting of the commercial DSA (Ti/RuO₂-IrO₂) anode and graphite cathode. It was found that the Fe-ZSM-5 zeolite greatly accelerated the degradation of lindane, with the degradation rate constant more than 8 times higher than that without Fe-ZSM-5. In addition, the Fe-ZSM-5 zeolite widened the working pH range from 3 to 11, while efficient degradation of lindane in the absence of Fe-ZSM-5 was only obtained at pH ≤ 5. The degradation of lindane was primarily due to reductive dechlorination mediated by atomic H* followed by ^•OH oxidation. Fe-ZSM-5 zeolite could enrich lindane, H*, and ^•OH on its surface, thus provided a suitable local environment for lindane degradation. The Fe-ZSM-5 zeolite exhibited high stability and reusability, and reduced the energy consumption. This research provides a potential reduction-oxidation strategy for removing organochlorine compounds through a cost-efficient Fe-ZSM-5 catalytic electrochemical system.