Effects of foreign metal doping on the step-by-step oxidation process in M-OMS-2 catalyzed activation of PMS

Xinquan Zhou; Qindi Zhao; Jia Wang; Xuefeng Wei; Ruichang Zhang; Songlin Wang; Peng Liu; Zhuqi Chen

doi:10.1016/j.jhazmat.2022.128773

Effects of foreign metal doping on the step-by-step oxidation process in M-OMS-2 catalyzed activation of PMS

J Hazard Mater. 2022 Jul 15:434:128773. doi: 10.1016/j.jhazmat.2022.128773. Epub 2022 Mar 25.

Authors

Xinquan Zhou¹, Qindi Zhao², Jia Wang³, Xuefeng Wei¹, Ruichang Zhang¹, Songlin Wang³, Peng Liu⁴, Zhuqi Chen⁵

Affiliations

¹ College of Chemical Engineering & Pharmaceutics, Henan University of Science and Technology, Luoyang, Henan 471023, PR China.
² Hubei Key laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
³ Hubei Provincial Engineering Laboratory of Solid Waste Treatment, Disposal and Recycling; Huazhong University of Science and Technology, Wuhan 430074, PR China; School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China.
⁴ Hubei Key laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: pengliu@hust.edu.cn.
⁵ Hubei Key laboratory of Material Chemistry and Service Failure, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China; Key Laboratory of Material Chemistry for Energy Conversion and Storage, Ministry of Education, School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, PR China. Electronic address: zqchen@hust.edu.cn.

PMID: 35427977
DOI: 10.1016/j.jhazmat.2022.128773

Abstract

Various metal cations M (M = Mg²⁺, Ca²⁺, Zn²⁺, Cu²⁺, Fe³⁺) were doped into the tunnel of manganese octahedral molecular sieve (OMS-2). Redox-inactive metal (Ca, Mg and Zn) doped OMS-2 exhibited better peroxymonosulfate (PMS) catalytic activity than redox metal-doped Cu-OMS-2 and Fe-OMS-2. Redox-inactive metals doping improves the conductivity and reducibility of the catalyst, while transition metal doping reduces the dispersion of manganese. More importantly, the degradation of ACE can be divided into two stages. In the first stage, ACE was oxidized dominantly through mediated electron transfer process. Subsequently, singlet oxygen (¹O₂) gradually dominated oxidative degradation in the second stage, which was derived from the reaction between superoxide radical (O₂^•-) and metastable manganese intermediates. The long half-life of O₂^•- on the surface of OMS-2 ensured the delay generation of ¹O₂. This study not only provides a new idea for improving the efficiency of heterogeneous catalysts activation of PMS, but also meaningful for the in-depth study of multiple reaction mechanisms in PMS activation processes.

Keywords: Conductivity; Mn dispersion; Redox-inactive metals; Reducibility modulation; Step-by-step oxidation.