Carbon-nanotube-doped Pd-Ni bimetallic three-dimensional electrode for electrocatalytic hydrodechlorination of 4-chlorophenol: Enhanced activity and stability

Yifan Wu; Ling Gan; Shupeng Zhang; Haiou Song; Chang Lu; Wentao Li; Zheng Wang; Bicun Jiang; Aimin Li

doi:10.1016/j.jhazmat.2018.05.034

Carbon-nanotube-doped Pd-Ni bimetallic three-dimensional electrode for electrocatalytic hydrodechlorination of 4-chlorophenol: Enhanced activity and stability

J Hazard Mater. 2018 Aug 15:356:17-25. doi: 10.1016/j.jhazmat.2018.05.034. Epub 2018 May 16.

Authors

Yifan Wu¹, Ling Gan¹, Shupeng Zhang², Haiou Song³, Chang Lu¹, Wentao Li¹, Zheng Wang¹, Bicun Jiang¹, Aimin Li⁴

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China.
² State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, PR China.
³ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; School of Environment, Nanjing Normal University, Nanjing, 210097, PR China; National Engineering Research Center for Organic Pollution Control and Resources Reuse, Nanjing 210023, PR China. Electronic address: songhaiou2011@126.com.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, PR China; National Engineering Research Center for Organic Pollution Control and Resources Reuse, Nanjing 210023, PR China. Electronic address: liaimin@nju.edu.cn.

PMID: 29804010
DOI: 10.1016/j.jhazmat.2018.05.034

Abstract

A novel composite bimetallic electrode, palladium-nickel/multi-walled carbon nanotubes/graphite felt (Pd-Ni/MWCNTs/GF), was synthesized for the electrocatalytic hydrodechlorination of 4-chlorophenol (4-CP). GF with a three-dimensional structure was used as the electrode substrate, and doped with MWCNTs, which can improve the GF conductivity and serve as a skeleton for metal loading. Ni and Pd were deposited on the electrode surface stepwise to obtain a well-aligned, highly active and stable Pd-Ni/MWCNTs/GF electrode. The Pd-Ni/MWCNTs/GF cathode showed a high reactivity for the electrocatalytic hydrodechlorination of 4-CP; up to 100% removal of 4-CP was achieved within 30 min, and followed pseudo-first-order kinetics with a rate constant of 0.162 min^-1. Compared with other cathodes, the Pd-Ni/MWCNTs/GF electrode showed superior performance in 4-CP reduction. Excessive current will lower the reaction efficiency and current efficiency because of hydrogen evolution, and acidic solution conditions are more conducive to electrocatalytic reactions. Experiments confirmed that the Ni had a small amount of loss under acidic conditions but remained stable under neutral and alkaline conditions, whereas the loss of Pd for different pH values was constantly low. In cycle tests, the bimetallic electrode exhibits a better reactivity and stability than the single-metal Pd electrode in the long-term.

Keywords: 4-chlorophenol; Bimetallic electrode; Electrocatalytic hydrodechlorination; Pd-Ni/MWCNTs/GF.