Efficacy and mechanism of peroxymonosulfate activation by single-atom transition metal catalysts for the oxidation of organic pollutants: Experimental validation and theoretical calculation

Jiahui Hu; Yubin Zou; Yin Li; Yanan Xiao; Mu Li; Lin Lin; Bing Li; Xiao-Yan Li

doi:10.1016/j.jcis.2023.04.093

Efficacy and mechanism of peroxymonosulfate activation by single-atom transition metal catalysts for the oxidation of organic pollutants: Experimental validation and theoretical calculation

J Colloid Interface Sci. 2023 Sep:645:1-11. doi: 10.1016/j.jcis.2023.04.093. Epub 2023 Apr 25.

Authors

Jiahui Hu¹, Yubin Zou², Yin Li¹, Yanan Xiao¹, Mu Li², Lin Lin¹, Bing Li³, Xiao-Yan Li⁴

Affiliations

¹ Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China; Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
² Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China; Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China.
³ Guangdong Provincial Engineering Research Center for Urban Water Recycling and Environmental Safety, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China; Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China. Electronic address: bingli@sz.tsinghua.edu.cn.
⁴ Institute of Environment and Ecology, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China; Tsinghua-Berkeley Shenzhen Institute, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, China; Environmental Engineering Research Centre, Department of Civil Engineering, The University of Hong Kong, Hong Kong, China. Electronic address: xlia@hku.hk.

PMID: 37126999
DOI: 10.1016/j.jcis.2023.04.093

Abstract

Single-atom catalysts can activate peroxymonosulfate (PMS) to enhance its oxidation of organic pollutants in water treatment. We synthesized a series of carbon-supported single-atom transition metal catalysts (MnN@C, FeN@C, CoN@C, NiN@C, and CuN@C) with similar compositions and structures. Their catalytic activity toward PMS activation and oxidation mechanisms were investigated using acid orange 7 (AO7) as a model pollutant. The degradation rate (min^-1·mol^-1·g·m^-2) of AO7 followed order: FeN@C/PMS (7.576 × 10³) > MnN@C/PMS (5.104 × 10³) > CoN@C/PMS (1.919 × 10³) ≫ NiN@C/PMS (0.058 × 10³) > CuN@C/PMS (0.035 × 10³). Electron transfer mediated by surface-activated PMS was found to be the main regime of AO7 oxidation in the catalytic systems. Density functional theory calculations indicated that the degradation of AO7 was promoted by the intense adsorption of PMS and the electron transfer between AO7 and the surface-activated PMS on the catalyst. The cleavage of the naphthalene ring and the azo group was the primary degradation pathway. The toxicity of the products was significantly reduced. This research provides valuable findings for preparing highly efficient single-atom transition metal catalysts for PMS-based degradation of toxic and refractory organic pollutants from water.

Keywords: Acid orange 7; Density functional theory; Mediated electron-transfer regime; Peroxymonosulfate activation; Single-atom catalysts.