Supported palladium nanoparticles as highly efficient catalysts for radical production: Support-dependent synergistic effects

Yong Feng; Hailong Li; Deli Wu; Changzhong Liao; Yiang Fan; Po-Heng Lee; Kaimin Shih

doi:10.1016/j.chemosphere.2018.05.047

Supported palladium nanoparticles as highly efficient catalysts for radical production: Support-dependent synergistic effects

Chemosphere. 2018 Sep:207:27-32. doi: 10.1016/j.chemosphere.2018.05.047. Epub 2018 May 9.

Authors

Yong Feng¹, Hailong Li², Deli Wu³, Changzhong Liao⁴, Yiang Fan⁵, Po-Heng Lee⁶, Kaimin Shih⁷

Affiliations

¹ Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR. Electronic address: fengy@hku.hk.
² Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR; School of Energy Science and Engineering, Central South University, Changsha 410083, People's Republic of China. Electronic address: hailong_li@126.com.
³ State Key Laboratory of Pollution Control and Resources Reuse, School of Environmental Science & Engineering, Tongji University, Shanghai 200092, People's Republic of China. Electronic address: wudeli@tongji.edu.cn.
⁴ Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR; Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Guangdong Institute of Eco-Environmental Science & Technology, Guangzhou, People's Republic of China. Electronic address: liaocz29@connect.hku.hk.
⁵ Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR. Electronic address: fanyiang@connect.hku.hk.
⁶ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong. Electronic address: phlee@polyu.edu.hk.
⁷ Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR. Electronic address: kshih@hku.hk.

PMID: 29772421
DOI: 10.1016/j.chemosphere.2018.05.047

Abstract

Supported metallic palladium (Pd) acts as a real catalyst for peroxymonosulfate (PMS) activation to produce highly oxidizing species. However, the species produced are surface-bound in nature, and their use for pollutant degradation requires an inert supporting material to minimize the surface scavenging effect. In this study, we synthesized Pd nanoparticles (NPs) on different supporting materials (Al₂O₃, TiO₂, SiO₂, g-C₃N₄, C, and TiC), and compared their reactivity toward PMS activation for the first time. Experiments with 1,4-dioxane as a target pollutant showed that Pd/SiO₂ had the highest reactivity of degrading 1,4-dioxane under acidic and neutral conditions, potentially due to the active interaction between SiO₂ and PMS. However, Pd/Al₂O₃ had the greatest value of around 107% in the conversion of PMS to radicals. The ready oxidation of methanol to formaldehyde and degradation of 1,4-dioxane suggest that the activation of PMS by all the supported Pd NPs proceeded via a radical mechanism. These findings are critical to the development of efficient composite catalysts and the scientific understanding of observing different active species produced by Pd-catalyzed PMS.

Keywords: 1,4-Dioxane; Peroxymonosulfate; Radicals; Supported Pd; Synergistic effects.

MeSH terms

Catalysis
Dioxanes / chemistry*
Nanoparticles / chemistry*
Palladium / chemistry*

Substances

Dioxanes
Palladium
1,4-dioxane