Recently, Professor Liu Jingfu's Studio at HIAS School of Environment has made progress in the research and modulation strategy of interfacial behavior in the electrocatalytic decontamination process. The research findings were published in Environmental Science & Technology under the title "Enhancing Electrocatalytic Hydrodechlorination through Interfacial Microenvironment Modulation" (DOI: 10.1021/acs.est.2c07462).
Electrochemical reduction (ER) is an effective approach to the treatment of pollutants as it efficiently converts pollutants such as oxyanions,halogenated persistent organic pollutants and disinfection by-products to purify drinking water. In addition, the ER process catalyzes N2 and CO2, showing great potential in addressing issues related to global warming, energy and famine. However, the problems of sluggish reaction kinetics and low utilization of electric energy have limited the applicability of the process of ER catalyzing reactions in aqueous media.
The paper systematically studies the surface microstructure, wettability, and H2 generation/escape behavior of the electrodes. It is found that the three-dimensional accumulation of Pd/C leads to the formation of dense nano/micropores on the electrode surface, rendering it highly hydrophobic. The H2 generated by the hydrogen evolution reaction (HER) in the ER process is easy to accumulate in the nano/micropores, changing the solid-liquid (catalyst-water) biphase interface into a solid-gas (H2)-liquid three-phase interface, significantly inhibiting material (water molecules, contaminants) and charge transfer. The strong hydrophobicity can be improved by adding PEG and other hydrophilic polymers to block the pores and reduce the surface tension. In addition to inhibiting electrochemical hydrogen evolution and reducing impedance, the use of PEG can also promote the dissociation of more water molecules, so as to produce more active hydrogen. More importantly, the change in the microenvironment of the catalytic interface effectively reduces the thickness of the diffusion layer and improved the transport kinetics of 2,4-dichlorophenol (2,4-DCP). The activity and Faraday efficiency of PEG-modified electrodes in the electrochemical hydrodehalogenation of 2,4-DCP can be increased by 4–5 times In addition, this microenvironmental modulation strategy provides a generic approach that can be compatible with other approaches, such as optimizing the structure of Pd sites to improve intrinsic catalytic activity, thereby increasing catalytic activity and Faraday efficiency.
The first author of the paper is Fan Zhimin, a master's student enrolled in 2020 at the School of Environment, Hangzhou Institute of Advanced Studies, UCAS, and the corresponding author is Professor Liu Rui. The research was supported by the National Natural Science Foundation of China and the fund for excellent members of the Youth Innovation Promotion Association of the Chinese Academy of Sciences.
Link of the paper: https://pubs.acs.org/doi/10.1021/acs.est.2c07462
Typesetter | Yan Hao
Source | WeChat official account "UCAS HIAS School of Environment"
Executive Editor | Yan Hao
