MnO 2 -Supported Pd Nanocatalyst for Efficient Electrochemical Reduction of 2,4-Dichlorobenzoic Acid

Yaxuan Peng and Meiyan Wang ()
Additional contact information
Yaxuan Peng: School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300400, China
Meiyan Wang: School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300400, China

Clean Technol., 2025, vol. 7, issue 4, 1-17

Abstract: Chlorobenzoic acids (CBAs) are a group of chlorinated persistent environmental pollutants with hard biodegradability, high water solubility, and well-documented carcinogenic and endocrine-disrupting properties. Electrocatalytic hydrodechlorination (ECH) is a highly efficient method under mild conditions without harmful by-products, but the ECH process commonly requires adding precious metal catalysts such as palladium (Pd). To address the economic constraints and more effective utilization of Pd, a palladium/manganese dioxide (Pd/MnO 2 ) composite catalyst was developed in this study by chemical deposition. This method utilized the excellent electrochemical activity of MnO 2 as a carrier as well as the hydrogen storage and activation capacity of Pd. The test showed the optimal Pd loading was 7.5%, and the removal percent of 2,4-dichlorobenzoic acid (2,4-DCBA), a typical CBA, reached 97.3% using 0.5 g/L of Pd/MnO 2 after 120 min of electrochemical reaction. Under these conditions, the dechlorination percent can also be as high as 89.6%. A higher current density enhanced the dechlorination efficiency but showed the lower current utilization efficiency. In practical applications, current density should be minimized on the premise of compliance with the water treatment requirement. Mechanistic studies showed that MnO 2 synergistically promoted hydrolysis dissociation and hydrogen spillover and facilitated Pd-mediated adsorption of atomic hydrogen (H*) for dehydrogenation of 2,4-DCBA. The presence of MnO 2 can effectively disperse the loaded Pd and reduce the amount of Pd via the above process. The catalyst exhibited excellent stability over multiple cycles, and the 2,4-DCBA removal could still reach more than 80% after the five cycles. This work establishes electrocatalytic strategies for effectively reducing Pd usage and maintaining high removal of typical CBAs to support CBA-related water treatment.

Keywords: MnO 2; 2,4-dichlorobenzoic acid; Pd; electrocatalytic reduction; dechlorination (search for similar items in EconPapers)
JEL-codes: Q2 Q3 Q4 Q5 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/2571-8797/7/4/102/pdf (application/pdf)
https://www.mdpi.com/2571-8797/7/4/102/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jcltec:v:7:y:2025:i:4:p:102-:d:1792326

Access Statistics for this article

Clean Technol. is currently edited by Ms. Shary Song

More articles in Clean Technol. from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().